Treat punctuation as words and as word separators

[kitbdev]

• fixes Inconsistent editor movement near arithmetic operators #92981

Treat punctuation as words and word separators.
This affects behavior in TextEdit, LineEdit, and RichTextLabel for word selection and operations.

Changed a test for ui_text_backspace_word since a period after a word is now separate and won't be removed together. This matches the behavior of other editors.

• Added simple test for custom word separators from Enable custom separators to treat different characters as words #92514.
• Added tests to prevent issues like Inconsistent and Broken Skipping Cursor in Editor - Godot 4.3 Beta 2 Custom #93618, Double clicking on a word can select prior not character symbol #69254, or Double clicking CJK text does not select the word under the cursor #75808.

[vgezer]

Thanks for noticing and fixing this. Also for the tests :)

[kitbdev]

It looks like adding just text_edit->set_text(U"👏👏👏 👏👏"); in a test will cause a leak. See https://github.com/kitbdev/godot/actions/runs/10563094361/job/29262539610#step:17:643 for this commit kitbdev@7653fb6.

I guess TextEdit isn't properly cleaning up when it gets deleted?

[bruvzg]

It looks like adding just text_edit->set_text(U"👏👏👏 👏👏"); in a test will cause a leak.

Are you referring to /lib/x86_64-linux-gnu/libfontconfig.so.1+ leak? This is an issue with the external library (👏 is not part of the editor fonts, so it's trying to load system font as fallback). The library is not part of Godot but part of Linux distro, so I'm not sure if we can do anything with it. Probably should be ignored, or we can add a subset of emoji font specifically for tests.

[kitbdev]

Thanks! I can remove the emoji test for now, it's not that important for this pr.

[kitbdev]

The other languages I was using were also causing issues, so I removed that test from this PR.