Fix #20826 - Numpad numbers no longer work to select note duration.

Fixed by blocking the creation (and pooling) of QAction creation for shortcuts with multiple alternatives in different states (like the 'common' and TAB-specific variants of "pad-note-..." shortcuts)

A rather detailed description of the implementation (regarding both the original, faulty, implementation and this fix) has been added to the mscore/shortcut.h file
fix #20832: Crash after adding accidental
merge doit/fall with glissando palette
Enabled all Capella testcases
Force <Beam> tags
fix #20893 and 20894
fix #20895
Fix crash when displaying shortcut preferences
fix #20896
fix #20891
Merge pull request #316 from lvinken/20581-capx-impl-3

Enabled all Capella testcases
Merge pull request #318 from lvinken/capella-import-fixes

Capella import fixes
fix capella test
Add support for "NumPad" qualifier in textual representations of key sequences both in dlg boxes and in xml files.

Also allows to remove the <code> tag from shortcuts.xml
fix #20904: Not possible to enter a - or space in lyrics via Ctrl key
fix #20916: Importing 1.x score containing no measure causes crash
new grouping implementation, dialog for changing grouping for a timesig
fixes for timesig dialog
fix #20475
Merge pull request #315 from mgavioli/Fix_20826_Numpad_note_duration_shortcuts

Fix #20826 - Numpad numbers no longer work to select note duration.