Add default Text editor for Email HTML Text format to CKEditor5

Problem/Motivation

Symfony Mailer is using the Email HTML text format as the default format for emails
But it is not using an visual editors

Proposed resolution

• Change text editor to CKEditor 5 for the Email HTML text format
• Add a default set of command, styling buttons, and filters
• Allow for the "Replaces global and entity tokens with their values" filter to be able to use passed tokens in Email Templates

Remaining tasks

• ✅ File an issue about this project
• ❌ Addition/Change/Update/Fix to this project
• ❌ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support on feature change/addition
• ➖ User Guide Documentation support on feature change/addition
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ❌ Code review from 1 Varbase core team member
• ❌ Full testing and approval
• ❌ Credit contributors
• ❌ Review with the product owner
• ❌ Update Release Notes and Update Helper on new feature change/addition
• ❌ Release

Varbase update type

• ✅ No Update
• ➖ Optional Update
• ➖ Forced Update
• ➖ Forced Update if Unchanged

User interface changes

• N/A

API changes

• N/A

Data model changes

• N/A

Release notes snippet

• N/A