[sonic-config-engine] Update .gitignore (#5223)

- Ignore directories generated by building Python wheel package
- Move all sonic-config-engine ignores from the root .gitignore to src/sonic-config-engine/.gitignore

.gitignore

@@ -28,11 +28,6 @@ platform/*/docker-*/Dockerfile
 # Installer-related files and directories
 installer/x86_64/platforms/
 
-# Config engine
-src/sonic-config-engine/**/*.pyc
-src/sonic-config-engine/build
-src/sonic-config-engine/sonic_config_engine.egg-info
-
 src/sonic-py-common/**/*.pyc
 src/sonic-py-common/.eggs/
 src/sonic-py-common/build

src/sonic-config-engine/.gitignore

@@ -1,3 +1,7 @@
+**/*.pyc
+*.egg-info/
+.eggs/
+build/
 dist/
 tests/output
 tests/output2