CodeMirror 6 editor: Fix Quick Links conflict with other autocomplete plugins

[personalizedrefrigerator]

Summary

Updates Quick Links to use joplinExtensions.completionSource for autocomplete. This fixes conflicts with the CodeMirror 6 Snippets plugin (and other future autocomplete plugins) without changing this plugin's behavior.

Fixes personalizedrefrigerator/joplin-plugin-codemirror-6-snippets#1.

Testing

1. Add Quick Links as a development plugin and CodeMirror 6 Snippets
2. Set up CodeMirror 6 Snippets using a snippets note.
3. Add a link using Quick Links.
4. CodeMirror 6 snippets to fill a snippet -- verify that it works and uses the same autocomplete window as Quick Links.
5. Create a JavaScript code block, type @@function and verify that the CodeMirror builtin completion for function can be used.
6. Verify that CodeMirror 6 snippets can also be used in the code block.

Screencast_20240227_084823-1.webm

[personalizedrefrigerator]

CodeMirror.joplinExtensions requires Joplin 2.14.16 or greater.

[roman-r-m]

So probably worth updating app_min_version in the manifest?

[roman-r-m]

Or I guess it will take the other branch and keep working as before. Except previously there was activateOnTyping: true -- not needed anymore?

[personalizedrefrigerator]

Looking at the documentation again, it seems that activateOnTypingg defaults to true. As such, it shouldn't be needed in either case.

Or I guess it will take the other branch and keep working as before.

The goal of having two branches is to continue supporting older versions of Joplin. To make this clear, I should include a comment explaining the purpose of the if statement.

[roman-r-m]

The goal of having two branches is to continue supporting older versions of Joplin. To make this clear, I should include a comment explaining the purpose of the if statement.

No it's clear enough, I should have looked closer before sending that comment. All good. Thanks for the PR.