Restore 1.3 behaviour of Space for harmony

Space/Shift-Space will now stop at the next beat, note, rest or chord.
Merge pull request #265 from softins/chord-navigation

Restore 1.3 behaviour of Space for harmony
Fix #20488: time sigs are not created for TAB staves.

If "Show time sigs" is turned on for TAB's, no tiem sig is shown as the time sig element is not there.
Merge pull request #267 from mgavioli/Fix#20488_TAB_time_sigs_not_created

Fix #20488: time sigs are not created for TAB staves.