Fix Marked Text Input

[thecoolwinter]

Description

Fixes marked text input for sequences longer than one marked character. Also ensures marked text works consistently with multiple cursors and adds testing for the marked text functionality.

Also:

• Fixes a few lint markers in test files that have caused issues for others.
• Adds a public TextView.markedTextAttributes property for modifying the marked text attributes if desired.

Related Issues

• closes 🐞 When typing Chinese, sometimes pressing a key will get several more letters #37
• closes 🐞 Typing with Dictation results in duplicate characters #36
• closes 🐞 Input not cleared when using Chinese input method #26
• closes 🐞 Compile errors by SwiftLintPlugin CodeEditSourceEditor#188

Checklist

• I read and understood the contributing guide as well as the code of conduct
• The issues this PR addresses are related to each other
• My changes generate no new warnings
• My code builds and runs on my machine
• My changes are all related to the related issue above
• I documented my code

Screenshots

Screen.Recording.2024-06-22.at.12.45.56.AM.mov

[RonghuaHe]

Hello, the previous issue is resolved, but now we have a new issue:when using Chinese or Japanese input method, input part of Chinese or Japanese, and then press the enter key, the text will be accidentally hidden.

[thecoolwinter]

Hello, the previous issue is resolved, but now we have a new issue:when using Chinese or Japanese input method, input part of Chinese or Japanese, and then press the enter key, the text will be accidentally hidden.

I'll look into this again, thank you for bringing it up