Add a third "Tab Indicator" differentiating between "Current-Focused Tab" and "Current-Unfocused Tab"

[Yaron10]

STR:
Enable Draw a colored bar on active tab.
Give keyboard focus to a "not-editor" element (e.g. the Incremental Search Bar).

Result:
The Active tab focused indicator is used even when the tab does not have keyboard focus.

Suggested:
Three tab indicators.
1. "Current-Focused Tab".
2. "Current-Unfocused Tab".
3. "Current Tab in Other View".

-- The user would be able to instantly know if the editing window actually has keyboard focus.
-- The system color for "Active Window Title" could be set to "Current-Focused Tab".

Related: #8446.

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Notepad++ v7.8.9 (32-bit)
Build time : Sep 5 2020 - 02:32:39
Path : C:---\notepad++.exe
Admin mode : ON
Local Conf mode : ON
OS Name : Windows 7 Enterprise (32-bit)
OS Build : 7601.23964
Current ANSI codepage : 1255
Plugins : ComparePlus.dll HTMLTag_unicode.dll MenuIcons.dll PythonScript.dll _CustomizeToolbar.dll

[KnIfER]

I prefer a "Marked Tab Indicator" that indicates the file is prominent.`