JS updates and directory structure

[Spuds]

Removed as much jquery code from the editor plugins as possible
Add new serialize url encode function, remove jsonstring. Helps with moving from $.ajax to fetch api
Added scripts/editor and scripts/ext directories to clean up the scripts folder
Updated all of those calls

[codecov]

Codecov Report

Attention: Patch coverage is 38.46154% with 24 lines in your changes are missing coverage. Please review.

Project coverage is 33.08%. Comparing base (279a9df) to head (b338360).
Report is 1 commits behind head on development.

Files	Patch %	Lines
sources/subs/Editor.subs.php	62.50%	3 Missing ⚠️
sources/ElkArte/Controller/Register.php	33.33%	2 Missing ⚠️
sources/ElkArte/Controller/Reminder.php	0.00%	2 Missing ⚠️
sources/ElkArte/EmojiIntegrate.php	0.00%	2 Missing ⚠️
sources/ElkArte/Notifications/UserNotification.php	0.00%	2 Missing ⚠️
sources/ElkArte/Themes/Javascript.php	50.00%	2 Missing ⚠️
...ces/ElkArte/AdminController/ManageRegistration.php	0.00%	1 Missing ⚠️
sources/ElkArte/Controller/Auth.php	75.00%	1 Missing ⚠️
sources/ElkArte/Controller/Stats.php	0.00%	1 Missing ⚠️
sources/ElkArte/Modules/Drafts/Display.php	0.00%	1 Missing ⚠️
... and 7 more

Additional details and impacted files

@@                Coverage Diff                @@
##             development    #3766      +/-   ##
=================================================
- Coverage          34.30%   33.08%   -1.22%     
+ Complexity         16555    16552       -3     
=================================================
  Files                432      431       -1     
  Lines              84239    83650     -589     
=================================================
- Hits               28895    27679    -1216     
- Misses             55344    55971     +627     

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