Add standard text search and replace

[guanglinn]

This PR makes Markor support the standard text find/search and replace adopted by many other popular text editors.

#2164 #2341 #2582

Supported features are as follows:

1. Standard UI for text find & replace

2. Highlight all occurrences/matches

3. Highlight current match

4. Move to previous/next match

5. Match case

6. Match whole word

7. Use regular expression

8. Find in selection

9. Replace once

10. Replace all

11. Preserve case when replacing

12. Toggle to line based text search

[guanglinn]

Screenshot ↓

[gsantner]

Thanks for working on this and the screenshot! To me at least it looks quite complicated at first, user will next ask where can I replace only this highlighted one? Where can I replace all? Thats the two most important buttons to be easy recognizable

[guanglinn]

User will next ask where can I replace only this highlighted one?
Where can I replace all?

These two features have already been implemented in this PR, and these two buttons can popup tool tips, users can easily recognize it.

[guanglinn]

Sorry, this PR has been put on hold for a long time. I will continue to improve it in these days.

[guanglinn]

Icons are from microsoft/vscode-icons: Icons for Visual Studio Code

[gsantner]

Hello guanglinn, what did you mean with visual studio code icons?

If a option viable, at Markor normal Android icon set is used

[guanglinn]

I mean, the icons used for this new find & replace are from vscode-icons, this is a open source icon set, and it's nice, so I just made a declaration here to indicate that we used it.

[guanglinn]

We can switch from standard text search to the original line based search.

petal_20260127_005257.mp4