Prevent data loss: migrate text fields with conflicting text_processing setting as formatter text fields

Re-roll of #20 for latest 10.1.x updates.

CHanging the issue title here for clarity, as failing to migrate something is not data loss. The data remains right where it's supposed to be.

fjgarlin → changed the visibility of the branch 11.x to hidden.

fjgarlin → changed the visibility of the branch 3213636-prevent-data-loss to hidden.

The patch was no longer applying so I created a MR based on it that would apply. I'm not sure if it should go back to Needs Review after #22

The Migrate Drupal Module was approved for removal in 📌 [Policy] Migrate Drupal and Migrate Drupal UI after Drupal 7 EOL Fixed .

This is Postponed. The status is set according to two policies. The Remove a core extension and move it to a contributed project → and the Extensions approved for removal → policies.

The deprecation work is in 📌 [12.x] [Meta] Tasks to remove Migrate Drupal module Postponed and the removal work in 📌 [12.x] [Meta] Tasks to remove Migrate Drupal module Postponed .

Migrate Drupal will not be moved to a contributed project. It will be removed from core after the Drupal 12.x branch is open.