[docker-databse]: Revise database_global schema for dpu (#17443)

### Why I did it
Revise DPU's database_global.json schema to achieve a more general design

### How I did it
1. Remove databse_type
2. Add a new field databse_name

dockers/docker-database/database_global.json.j2

@@ -26,7 +26,7 @@
 {% if dpu_cnt > 0 %}
 {% for dpu in range(dpu_cnt) %}
         {
-            "database_type" : "dpudb",
+            "database_name" : "dpu{{dpu}}",
             "include" : "../../redisdpu{{dpu}}/sonic-db/database_config.json"
 {% if dpu == dpu_cnt-1  %}
         }