TinyMCE Classic Block: fix "Advanced Link" modal

[azaozz]

The "Advanced Link" modal doesn't work reliably in the Classic Block instance. Sometimes it doesn't insert a link, sometimes it inserts it at the beginning of the text instead of the cursor position.

This was reported for Gutenberg some time ago. See ​https://github.com/WordPress/gutenberg/issues/7932 and the 6-7 issues closed as duplicates. Opening this ticket here as it is an issue with one of our old custom TinyMCE plugins.

[azaozz]

There are few reasons for these bugs. Most importantly the editor instance is inline and some "utility" functions work a bit differently.

In 46071.diff:

• Refresh the wpLink modal and wplink editor plugin a bit.
• Always select the (newly inserted or existing) link node after the modal has been opened. Passing it from the editor plugin breaks as the editor content is reloaded on editor.blur(), and opening the modal and clicking in it triggers that.
• Remove outdated editor.focus() on opening the modal (was bad for accessibility).

Tested in Firefox, Chrome and Edge on Win10.

[iseulde]

Ok, looks good.

[azaozz]

In 44696:

TinyMCE Classic Block: fix the Advanced Link modal (accessible when clicking on the cogwheel in the inline link modal in a Classic Block).

Fixes #46071.

[ocean90]

In 44699:

TinyMCE Classic Block: Remove unused variable.

See #46071.

[noisysocks]

#44348 was marked as a duplicate.

[pento]

#45678 was marked as a duplicate.