feat: add optional schema for Postgres metadata tables (#6764)

* feat(meta): add optional schema for Postgres metadata tables

- Add `schema` option to specify a custom schema for metadata tables
- Update `PgStore` and `PgElection` to support optional schema
- Modify SQL templates to use schema when provided
- Add tests for schema support in Postgres backend

Signed-off-by: Logic <zqr10159@dromara.org>

* refactor(meta): remove unused `create_schema_statement` and simplify `PgSqlTemplateFactory`

- Remove `create_schema_statement` from `PgSqlTemplateSet` struct
- Simplify `PgSqlTemplateFactory` by removing `new` method and merging it with `with_schema`
- Update related tests to reflect these changes

Signed-off-by: Logic <zqr10159@dromara.org>

* refactor(meta-srv): remove unused imports

- Remove unused import of BoxedError from common_error::ext- Remove unused import of TlsOption from servers::tls

Signed-off-by: Logic <zqr10159@dromara.org>

* build(meta): update Postgres version and add error handling imports

- Update Postgres version to 17 in docker-compose.yml
- Add BoxedError import for error handling in meta-srv

Signed-off-by: Logic <zqr10159@dromara.org>

* feat(postgres): add support for optional schema in PgElection and related components

Signed-off-by: Logic <zqr10159@dromara.org>

* feat(postgres): add support for optional schema in PgElection and related components

Signed-off-by: Logic <zqr10159@dromara.org>

* fix(develop): update Postgres schema commands to specify host

Signed-off-by: Logic <zqr10159@dromara.org>

* refactor(postgres): simplify plugin options handling and update SQL examples

Signed-off-by: Logic <zqr10159@dromara.org>

* refactor(postgres): simplify plugin options handling and update SQL examples

Signed-off-by: Logic <zqr10159@dromara.org>

* fix(postgres): update meta_election_lock_id description for optional schema support

Signed-off-by: Logic <zqr10159@dromara.org>

* fix(postgres): add health check and fallback wait for Postgres in CI setup

* fix(postgres): update Docker setup for Postgres and add support for Postgres 15

* fix(postgres): remove redundant Postgres setup step in CI configuration

* Update tests-integration/fixtures/postgres/init.sql

Co-authored-by: Weny Xu <wenymedia@gmail.com>

* Update .github/workflows/develop.yml

* Update tests-integration/fixtures/docker-compose.yml

* Update src/common/meta/src/kv_backend/rds/postgres.rs

Co-authored-by: Weny Xu <wenymedia@gmail.com>

* Update src/common/meta/src/kv_backend/rds/postgres.rs

Co-authored-by: Weny Xu <wenymedia@gmail.com>

* Update src/common/meta/src/kv_backend/rds/postgres.rs

Co-authored-by: Weny Xu <wenymedia@gmail.com>

* Update src/common/meta/src/kv_backend/rds/postgres.rs

Co-authored-by: Weny Xu <wenymedia@gmail.com>

* fix: Refactor PostgreSQL backend to support optional schema in PgStore and related SQL templates

* feat: Update PostgreSQL configuration and add PG15 specific integration tests

* feat: Update PostgreSQL configuration and add PG15 specific integration tests

* refactor(postgres): update test schemas from 'greptime_schema' to 'test_schema'

* Update .github/workflows/develop.yml

* refactor: minor factor

Signed-off-by: WenyXu <wenymedia@gmail.com>

* chore: apply suggestions

Signed-off-by: WenyXu <wenymedia@gmail.com>

* fix: fix unit test

Signed-off-by: WenyXu <wenymedia@gmail.com>

---------

Signed-off-by: Logic <zqr10159@dromara.org>
Signed-off-by: WenyXu <wenymedia@gmail.com>
Co-authored-by: Weny Xu <wenymedia@gmail.com>

.github/workflows/develop.yml

@@ -766,6 +766,8 @@ jobs:
           GT_ETCD_TLS_ENDPOINTS: https://127.0.0.1:2378
           GT_ETCD_ENDPOINTS: http://127.0.0.1:2379
           GT_POSTGRES_ENDPOINTS: postgres://greptimedb:admin@127.0.0.1:5432/postgres
+          GT_POSTGRES15_ENDPOINTS: postgres://test_user:test_password@127.0.0.1:5433/postgres
+          GT_POSTGRES15_SCHEMA: test_schema
           GT_MYSQL_ENDPOINTS: mysql://greptimedb:admin@127.0.0.1:3306/mysql
           GT_KAFKA_ENDPOINTS: 127.0.0.1:9092
           GT_KAFKA_SASL_ENDPOINTS: 127.0.0.1:9093
@@ -819,6 +821,8 @@ jobs:
           GT_ETCD_TLS_ENDPOINTS: https://127.0.0.1:2378
           GT_ETCD_ENDPOINTS: http://127.0.0.1:2379
           GT_POSTGRES_ENDPOINTS: postgres://greptimedb:admin@127.0.0.1:5432/postgres
+          GT_POSTGRES15_ENDPOINTS: postgres://test_user:test_password@127.0.0.1:5433/postgres
+          GT_POSTGRES15_SCHEMA: test_schema
           GT_MYSQL_ENDPOINTS: mysql://greptimedb:admin@127.0.0.1:3306/mysql
           GT_KAFKA_ENDPOINTS: 127.0.0.1:9092
           GT_KAFKA_SASL_ENDPOINTS: 127.0.0.1:9093
@@ -850,4 +854,3 @@ jobs:
   #         mkdir -p ./bins/current
   #         tar -xvf ./bins.tar.gz --strip-components=1 -C ./bins/current
   #     - run: ./tests/compat/test-compat.sh 0.6.0
-