### Does this PR have any customer impact?
No
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Refactoring
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
Yes
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
Start porting schemas for documentdb api.
Introducing API_SCHEMA_NAME_V2, API_SCHEMA_INTERNAL_NAME_V2, API_CATALOG_SCHEMA_NAME_V2
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#### AI description (iteration 1)
#### PR Classification
Porting type/operator/schema into documentdb.
#### PR Summary
This pull request ports various types, operators, and schemas into documentdb as part of an ongoing effort.
- `pg_documentdb/sql/documentdb--0.24-0.sql`: Created multiple schemas and included various SQL files for query functions, operators, and metadata.
- `pg_documentdb/sql/operators/bson_dollar_operators--0.16-0.sql`: Updated operator definitions to use `__API_SCHEMA_INTERNAL_V2__`.
- `pgmongo/sql/operators/bson_dollar_negation_operators--1.15-1.sql` and `pg_documentdb/sql/operators/bson_dollar_negation_operators--0.16-0.sql`: Changed operator definitions to use `__API_SCHEMA_INTERNAL_V2__`.
- `Makefile.cflags`: Added checks for new schema variables `API_SCHEMA_NAME_V2`, `API_SCHEMA_INTERNAL_NAME_V2`, and `API_CATALOG_SCHEMA_NAME_V2`.
- `pg_documentdb/sql/schema/unique_shard_path_operator_class--0.24-0.sql`: Updated operator class definitions to use `__API_SCHEMA_INTERNAL_V2__`.
### Does this PR have any customer impact?
No
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Refactoring
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
Yes
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
Move type/operator/schema files from pg_helio_api -> pg_documentdb
Except udf files
----
#### AI description (iteration 1)
#### PR Classification
Code cleanup
#### PR Summary
This pull request moves type, operator, and schema files from the `pg_helio_api` directory to the `pg_documentdb` directory.
- Updated SQL include paths in multiple `pg_helio_api` SQL files to reference `pg_documentdb` directory.
- Modified `pgmongo` SQL files to include paths from `pg_documentdb` instead of `pg_helio_api`.
- Adjusted `validate_helio_extension_state.sh` script to account for new file paths.
- Updated `Makefile` in `pg_helio_api` to include the new directory structure.
- Changed include paths in `pg_documentdb_distributed` and `pg_helio_distributed` C source files to reflect the new directory structure.
Zinan Ren