create_table with text limits

What does this MR do?

This implements #337792 (closed) and removes create_table_with_constraints, which was using subtransactions.

We remove the helper in version 2 and extend the Rails' method create_table to support t.text :something, limit: 128 (adding the limit attribute).

Additional benefit: We get to use change again, because it's a standard Rails helper.

For in-flight MRs using create_table_with_constraints, this will raise and will have to be changed.

How to setup and validate locally (strongly suggested)

Example migration:

    create_table :db_guides do |t|
      t.bigint :stars, default: 0, null: false
      t.text :title, limit: 128
      t.text :notes, limit: 1024

      t.check_constraint 'stars > 1000', name: 'so_many_stars'
    end

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.