feat: preserve case in active window title and introduce optional IGNORECASE_window flag

[sl5net]

Problem

The active window title retrieval in:
scripts/py/func/get_active_window_title.py
forces all retrieved titles to lowercase using .lower(). This makes case-sensitive matching for the only_in_windows rule filter impossible and is counter-intuitive for users who see capitalized titles like 'Kate' or 'Konsole' on screen and write them as-is in their configurations.

Proposed Solution

[1, Preserve Case]
Remove the .lower() conversions in the window-title retrieval functions inside:
scripts/py/func/get_active_window_title.py

[2, Introduce 'IGNORECASE_window' Option]
Introduce an optional metadata flag/configuration key 'IGNORECASE_window'.

• If 'IGNORECASE_window' is specified, the window title matching for only_in_windows should be performed case-insensitively.
• Otherwise, perform a strict case-sensitive match against the original preserved casing of the active window title.