Desktop: Resolves #10199: Show "ctrl-click to open" tooltip for links in the rich text editor (markdown notes only)

[personalizedrefrigerator]

Summary

This pull request shows a "ctrl-click to open link" tooltip by links in the rich text editor.

Resolves #10199.

Notes:

• This pull request only applies to markdown notes, as modified tooltips are added with Markdown-it and Turndown is used to restore the original tooltip when closing the Rich Text editor.
  • An alternative solution could be to override/update tooltips when loading a note in the Rich Text editor, then restore the tooltips when saving.
• If the user specifes a different tooltip using the "edit link" dialog or in markdown, that tooltip is shown instead.

This pull request has automated tests.

Screenshots

[personalizedrefrigerator]

• This pull request only applies to markdown notes, as Turndown is currently used to restore the original tooltip when closing the Rich Text editor.
  • An alternative solution could be to override/update tooltips when loading a note in the Rich Text editor, then restore the tooltips when saving.

This pull request also applies only to:

1. Markdown-style links ([example](https://example.com/ and not <a href="https://example.com/">Example</a>),
2. Links added before the last re-render (e.g. before opening the current note).

As such, I think the alternative solution described above would be better.

[personalizedrefrigerator]

For future reference, I'm linking this to #10215, which takes a similar approach.