Is there an existing issue for this?

• I have searched the existing issues

Description of the Issue

Currently no way for plugins to manipulate tab coloring, as is settable in N++'s View menu > Tab > Apply Color ...

Describe the solution you'd like.

Implementation of NPPM_GET_TABCOLORINDEX and NPPM_SET_TABCOLORINDEX as plugin commands.

Debug Information

Notepad++ v8.6.6   (64-bit)
Build time : May  6 2024 - 21:59:00
Path : C:\NotepadPlusPlus\Misc\_NoBackup\Releases\npp.8.6.6\npp.8.6.6.portable.x64\notepad++.exe
Command Line : -multiInst
Admin mode : OFF
Local Conf mode : ON
Cloud Config : OFF
Periodic Backup : ON
OS Name : Windows 11 Pro (64-bit)
OS Version : 23H2
OS Build : 22631.3447
Current ANSI codepage : 1252
Plugins : 
    mimeTools (3.1)
    NppConverter (4.6)
    NppExport (0.4)

Anything else?

A scripting reason for wanting to be able to get tab coloring is discussed here: https://community.notepad-plus-plus.org/post/94744