Percussion note entry: voices should not be pre-allocated for MIDI keyboard / virtual Piano

Describe the bug

Behavior in MS3: When you input percussion from the Drum Input Palette or using keyboard shortcuts, the voices are pre-allocated; that is, they are decided by settings in the "Edit drumset" dialog.

However, if you input via the virtual Piano or an external MIDI keyboard, there is NO pre-allocation of voices; the user chooses the voice for him/herself using the icons on the toolbar (or voice shortcuts).

Behavior in MS4 (regression): Now, however, the voices are always pre-allocated by the "Edit drumset" settings. The user has no control over the voice even when using the on-screen Piano or external MIDI keyboard.

To Reproduce

1. Create percussion staff
2. Open the Piano (P)
3. Choose voice 1 from the toolbar
4. Press C2 for bass drum

RESULT: Bass drum defaults to voice 2 rather than the voice 1 chosen by the user.

Expected behavior

The bass drum should have been entered in voice 1.

When entering notes into a percussion staff from the on-screen Piano or MIDI keyboard, voice allocation should be decided by the user (using the note input toolbar or voice shortcuts).

Note: IMV, there is a wider issue here. Why not remove pre-allocation of drumset voices altogether? It was probably designed to aid the beginner, but is clearly a cause of confusion.

Platform information

OS: Linux Mint 20.1, Arch.: x86_64, MuseScore version (64-bit): 4.0.2-230230504, revision: github-musescore-musescore-13f9eae

Reproduce the issue with a percussion staff, the virtual Piano, and an external MIDI keyboard, using voice 1 before pressing C2. Trace how these inputs differ from the Drum Input Palette and keyboard shortcuts, especially the Edit drumset voice allocation. Done means Piano and MIDI input honor the user-selected voice while existing drum input behavior remains understood and tested.