String-related fixes and improvements.

[VladiStep]

Description

1. Fixed missing UndertaleString name in the tab titles.
2. Fixed crash on new UndertaleString addition.
3. "Copy name to clipboard" feature now works with UndertaleString items.
4. UndertaleString tab title updates on string content change and properly shortens if it contains tab characters.
5. Fixed all the instances of "Name property not found on object of type ..." WPF binding warning.
6. An empty UndertaleString is displayed as "(empty string)".
7. Fixed HighlightObject() UndertaleString highlighting - the asset list will scroll to just added string; errors are written to debug console if silent = true.
8. Fixed some typos.
9. Content of a new UndertaleString is "string(index)".

Closes #975, closes #976

[github-actions]

Download the artifacts for this pull request here:

GUI:

• GUI-windows-latest-isBundled-false-isSingleFile-false
• GUI-windows-latest-isBundled-false-isSingleFile-true

CLI:

• CLI-macOS-latest-isBundled-false
• CLI-ubuntu-latest-isBundled-false
• CLI-windows-latest-isBundled-false

[Miepee]

• I dont think the tab shortening works (from the amount of tabs in there, it shouldnt even display #define matrix_world)
  
• there should be some default name on new string creation. this makes it very hard to edit if i misclicked somewhere else ("new string" would probably be enough)
  
• you should mention that the pr fixes Impossible to add strings anymore via right click #975 and Copy name to clipboard doesn't work with strings #976

[VladiStep]

The first screenshot is "Strings" list - it has 256 characters limit

[Miepee]

Ah, whoops.