feat: rename typeorm_metadata table

[varanauskas]

Description of change

This new feature adds a new connection option metadataTableName that allows for renaming of the typeorm_metadata table

This was needed to allow users to rename the typeorm_metadata table if they needed it.
For example multiple typeorm services using the same database could clash on creating/updating the table in their migrations.

Fixes: #7266

Pull-Request Checklist

• Code is up-to-date with the master branch
• npm run lint passes with this change
• npm run test passes with this change
  Unable to run full test suite, due to missing SAP Hana (and perhaps others)
  But added a new test suite that is passing
• This pull request links relevant issues as Fixes #0000
• There are new or updated unit tests validating the change
• Documentation has been updated to reflect this change
  English documentation has been updated, CN documentation updated partially
• The new commits follow conventions explained in CONTRIBUTING.md

[varanauskas]

This is my first PR in TypeORM, so could you review the design choice I made:

I have moved the canonical name of the typeorm_metadata table to Connection (comparable to how namingStrategy is set up) as both the SchemaBuilder and QueryRunner needed it, and they both had access to the connection.
Should the canonical name (TYPEORM_METADATA_TABLE_NAME || "typeorm_metadata") be moved elsewhere?

(Mirrors PR #8469, changed source branch name)

[pleerock]

Ideally this name should be in the naming strategy itself, however I see migrationsTableName is already not there. So I'm okay with current implementation. I think this PR can be merged.

[pleerock]

Thank you for contribution! 🎉