>
### Description
>
While adding [insert mutation schema parser for MSSQL backend](https://github.com/hasura/graphql-engine-mono/pull/2141) I also included [identity](https://en.wikipedia.org/wiki/Identity_column) notion to table columns across all backends. In MSSQL we cannot insert any value (even `DEFAULT` expression) into Identity columns. This behavior of identity columns is not same in Postgres as we can insert values. This PR drops the notion of identity in the column info. The context of identity columns for MSSQL is carried in `ExtraTableMetadata` type.
### Changelog
- [x] `CHANGELOG.md` is updated with user-facing content relevant to this PR. If no changelog is required, then add the `no-changelog-required` label.
### Affected components
- [x] Server
- [ ] Console
- [ ] CLI
- [ ] Docs
- [ ] Community Content
- [ ] Build System
- [x] Tests
- [ ] Other (list it)
### Related Issues
->
Fix https://github.com/hasura/graphql-engine/issues/7557https://github.com/hasura/graphql-engine-mono/pull/2378
GitOrigin-RevId: c18b5708e2e6107423a0a95a7fc2e9721e8a21a1
>
### Description
>
This PR is an incremental work towards [enabling insert mutations on MSSQL](https://github.com/hasura/graphql-engine-mono/pull/1974). In this PR, we generate insert mutation schema parser for MSSQL backend.
### Changelog
- [ ] `CHANGELOG.md` is updated with user-facing content relevant to this PR. If no changelog is required, then add the `no-changelog-required` label.
### Affected components
- [x] Server
https://github.com/hasura/graphql-engine-mono/pull/2141
GitOrigin-RevId: 8595008dece35f7fded9c52e134de8b97b64f53f
