More restore original db config in db rake tasks

[justinko]

Fixes #51830

Motivation / Background

This is just additional changes that would've been included in #46270

Detail

When running multiple db rake tasks in a single command, we should restore to the original "db config" in between each task.

Checklist

Before submitting the PR make sure the following are checked:

• This Pull Request is related to one change. Unrelated changes should be opened in separate PRs.
• Commit message has a detailed description of what changed and why. If this PR fixes a related issue include it in the commit message. Ex: [Fix #issue-number]
• Tests are added or updated if you fix a bug or add a feature.
• CHANGELOG files are updated for the changed libraries if there is a behavior change or additional feature. Minor bug fixes and documentation changes should not be included.

[justinko]

Working on test failures. Next time I'll run more tests before opening a pull.

[justinko]

Just passes through with no asserting -- didn't think it was important since the logic doesn't pertain to it.

I did build a version with some asserting (the configs are passed to it) so if that's what we want ... I can swap it out.

[driv3r]

I was about to create PR, but this looks closely related what I was looking into (but mysql only). TBH I would move the ActiveRecord::Tasks::DatabaseTasks.with_temporary_connection down to *DatabaseTasks, as well, especially MySQL one, which uses root user for database creation. So this

      def create
        establish_connection(configuration_hash_without_database)
        connection.create_database(db_config.database, creation_options)
        establish_connection
      end

Would become this instead

      def create
        ActiveRecord::Tasks::DatabaseTasks.with_temporary_connection(configuration_hash_without_database) do |conn|
           conn.create_database(db_config.database, creation_options)
        end
      end

Same would be for drop and purge. I see PostgreSQL also uses default postgres database.

[driv3r]

This solves the issue we had when running seeds after setting up other DB that primary, just like in the mentioned issue