Remove Unsupported JSONEditor Themes and Add-Ons

Problem/Motivation

In the interest of minimizing maintenance surface area within the module, integration for various themes, icon sets, and plugins that are infrequently used and largely unmaintained to date. If demand is heard for any of these to be re-added, a method may be explored for the editor to be cleanly hooked into to customize options and add related libraries.

Steps to reproduce

Settings changes

• Navigate to Patternkit JSON Library Settings (/admin/config/user-interface/patternkit/json)
• Theme selection should no longer be available
• Icon set options should no longer include removed options
• WYISWYG options should only list CKEditor5 if the CKEditor5 module is available

Database updates

• Database updates should run to...
  • Default the theme to Cygnet if a removed theme was in use
  • Remove icon set selection if a removed set was in use
  • Remove WYSIWYG selection if a removed option was in use

Maintained functionality

• Create a new Patternkit Example block in an overridden node layout
• The editor form should be styled using the Cygnet theme
• HTML fields should use the selected WYSIWYG editor if any

Proposed resolution

• Remove unsupported icon sets per the JSONEditor list of supported icons:
  • bootstrap2
  • bootstrap3
  • foundation2
  • foundation3
• Remove no longer supported/maintained JSONEditor themes:
  • jqueryui
  • bootstrap2
  • bootstrap3
  • bootstrap4
  • foundation3
  • foundation4
  • foundation5
  • foundation6
• Hide the theme selection input
• Remove no longer supported WYSIWYG options:
  • CKEditor4
  • Quill
  • ProseMirror

Remaining tasks

User interface changes

• Unsupported JSONEditor themes are removed as options
• JSONEditor theme selection input is hidden
• Unsupported JSONEditor icon sets are removed as options
• Unsupported JSONEditor WYSIWYG options are removed as options

API changes

None

Data model changes

None