Revert TinyMCE config bugfix prior to CMS 5.2 release

[maxime-rainville]

Acceptance criteria

• This bug fix is reverted (CMS 4.13 and 5.1). Use field editorconfig when sanitising content #10977

Related

• [Bug] TinyMCEConfig breaks when using option extended_valid_elements on a custom Config. #11141

PRs

• Revert "Use field editorconfig when sanitising content" #11180

[emteknetnz]

Assigning back to @GuySartorelli to manually run the merge-up workflow and ensure it ends up in 5.2.x-dev correctly for the rc release

[GuySartorelli]

Ensuring everything is merged up is part of the RC release process. Closing, but I will run the merge-up task.