Document fuzzy hash delisting feature in README

Add documentation for "Request hash delisting" context menu item
and automatic deduplication of fuzzy hashes.

Document fuzzy hash extraction feature in README

Add icons to context menus and update toolbar buttons icons

- Add missing icons to context menu items
- Replace PNG arrow icons with pixel-perfect SVG versions

Known issue: Last menu item icon may not display when positioned over
taskbar due to Thunderbird lazy loading bug.

Guard against malformed JSON in LDA mode header

Add dynamic module loading for TB 136+ support

Detect Thunderbird version at runtime and load modules using the
appropriate format (ESM for TB 136+ and JSM for older versions), ensuring
compatibility across releases.

Fix missing window argument in getScoreByHdr calls

Implement MIME decoding for XPC wrapped header

Replace "undefined" with "∅" for better clarity

- Changed "undefined" to empty set symbol (∅) for parsing results in the score header
- Display empty set symbol (∅) in notifications when no symbols are found

[Minor] Increase right margin for action header

Update max version to 130.*