feat: support postgresql inference store (#2310)

# What does this PR do?
* Added support postgresql inference store
* Added 'oracle' template that demos how to config postgresql stores
(except for telemetry, which is not supported currently)


## Test Plan

llama stack build --template oracle --image-type conda --run
LLAMA_STACK_CONFIG=http://localhost:8321 pytest -s -v tests/integration/
--text-model accounts/fireworks/models/llama-v3p3-70b-instruct -k
'inference_store'

llama_stack/providers/utils/kvstore/config.py

@@ -65,7 +65,7 @@ class SqliteKVStoreConfig(CommonConfig):
 class PostgresKVStoreConfig(CommonConfig):
     type: Literal[KVStoreType.postgres.value] = KVStoreType.postgres.value
     host: str = "localhost"
-    port: int = 5432
+    port: str = "5432"
     db: str = "llamastack"
     user: str
     password: str | None = None