fix #19985 - mark score dirty

after chnages to Menu -> Display -> Show
{Invisible|Unprintable|Frames|Page Margins}
Merge pull request #205 from Jojo-Schmitz/issue_#19985

fix #19985 - mark score dirty
small capitalization fix
add 'show staff' to palette cell properties
add missing gui update after deleting palette cell delete
rework of palettes & workspace