[DPB][YANG] Fix cases when boolean is used in different literal cases (#9418)

Fixes #9326

#### Why I did it
When we try execute DPB from CLI we have error:
`libyang[0]: Invalid value "False" in "has_global_scope" element. (path: /sonic-feature:sonic-feature/FEATURE/FEATURE_LIST[name='bgp']/has_global_scope)`
The reason for this issue is that has_global_scope and other have been stored in redis database with value False or True form capital letter:
```
   "FEATURE":{
      "bgp":{
         "auto_restart":"enabled",
         "has_global_scope":"False",
         "has_per_asic_scope":"True",
         "has_timer":"False",
         "high_mem_alert":"disabled",
         "state":"enabled"
      }
```
But yang model support boolean just in lowercase letters (https://datatracker.ietf.org/doc/html/rfc6020#section-9.5.1).
#### How I did it
Added boolean to sonic-types as typedef with different literal cases.

#### How to verify it
Run the command config interface breakout <breakout_mode>

**NOTE:**
To verify this fix, the following PRs that fix other problems in SONiC must be merged into master:
1) Azure/sonic-buildimage/pull/9075
2) Azure/sonic-buildimage/pull/9276

src/sonic-yang-models/tests/files/sample_config_db.json

@@ -1220,9 +1220,9 @@
         "FEATURE": {
             "bgp": {
                 "auto_restart": "enabled",
-                "has_global_scope": "false",
-                "has_per_asic_scope": "true",
-                "has_timer": "false",
+                "has_global_scope": "False",
+                "has_per_asic_scope": "True",
+                "has_timer": "False",
                 "high_mem_alert": "disabled",
                 "state": "enabled",
                 "set_owner": "local"

src/sonic-yang-models/tests/yang_model_tests/tests/feature.json

@@ -7,6 +7,11 @@
         "eStrKey": "Pattern",
         "eStr": ["enabled|disabled|always_enabled|always_disabled"]
     },
+    "FEATURE_WITH_INVALID_BOOLEAN_TYPE" : {
+        "desc": "Referring invalid feature boolean types.",
+        "eStrKey": "Pattern",
+        "eStr": ["false|true|False|True"]
+    },
     "FEATURE_WITH_INVALID_OWNER" : {
         "desc": "Referring invalid feature set_owner field.",
         "eStrKey": "Pattern",

src/sonic-yang-models/tests/yang_model_tests/tests_config/feature.json

@@ -7,9 +7,9 @@
                         "name": "database",
                         "state": "always_enabled",
                         "auto_restart": "always_enabled",
-                        "has_timer": "false",
-                        "has_global_scope": "true",
-                        "has_per_asic_scope": "true",
+                        "has_timer": "False",
+                        "has_global_scope": "True",
+                        "has_per_asic_scope": "True",
                         "set_owner": "local"
                     },
                     {
@@ -101,5 +101,21 @@
                 ]
             }
         }
+    },
+    "FEATURE_WITH_INVALID_BOOLEAN_TYPE": {
+        "sonic-feature:sonic-feature": {
+            "sonic-feature:FEATURE": {
+                "FEATURE_LIST": [
+                    {
+                        "name": "database",
+                        "state": "always_enabled",
+                        "auto_restart": "always_enabled",
+                        "has_timer": "FALSE",
+                        "has_global_scope": "TRUE",
+                        "has_per_asic_scope": "TRUE"
+                    }
+                ]
+            }
+        }
     }
 }

src/sonic-yang-models/yang-models/sonic-feature.yang

@@ -5,6 +5,10 @@ module sonic-feature{
     namespace "http://github.com/Azure/sonic-feature";
     prefix feature;
 
+    import sonic-types {
+        prefix stypes;
+    }
+
     description "Feature Table yang Module for SONiC";
 
     typedef feature-state {
@@ -53,22 +57,22 @@ module sonic-feature{
                 leaf has_timer {
                     description "This configuration identicates if there is
                                 timer associated to this feature";
-                    type boolean;
-                    default false;
+                    type stypes:boolean_type;
+                    default "false";
                 }
 
                 leaf has_global_scope {
                     description "This configuration identicates there will only one service
                                 spawned for the device";
-                    type boolean;
-                    default false;
+                    type stypes:boolean_type;
+                    default "false";
                 }
 
                 leaf has_per_asic_scope {
                     description "This configuration identicates there will only one service
                                 spawned per asic";
-                    type boolean;
-                    default false;
+                    type stypes:boolean_type;
+                    default "false";
                 }
 
                 leaf high_mem_alert {

src/sonic-yang-models/yang-models/sonic-flex_counter.yang

@@ -5,6 +5,10 @@ module sonic-flex_counter {
     namespace "http://github.com/Azure/sonic-flex_counter";
     prefix flex_counter;
 
+    import sonic-types {
+        prefix stypes;
+    }
+
     description "FLEX COUNTER YANG Module for SONiC OS";
 
     revision 2020-04-10 {
@@ -24,7 +28,7 @@ module sonic-flex_counter {
             }
 
             typedef flex_delay_status {
-                type boolean;
+                type stypes:boolean_type;
             }
 
             typedef poll_interval {

src/sonic-yang-models/yang-templates/sonic-types.yang.j2

@@ -217,6 +217,12 @@ module sonic-types {
         }
     }
 
+    typedef boolean_type {
+        type string {
+            pattern "false|true|False|True";
+        }
+    }
+
     typedef mac-addr-and-mask {
         type string {
             pattern "[0-9a-fA-F]{2}(:[0-9a-fA-F]{2}){5}|[0-9a-fA-F]{2}(:[0-9a-fA-F]{2}){5}/[0-9a-fA-F]{2}(:[0-9a-fA-F]{2}){5}";