Slow refresh with worktrees in side panel

Environment

GE master

Issue description

#12927 (with follow ups) added worktree to the sidepanel. If you have several worktree, refreshing now takes longer time, it can add a few seconds with a couple of worktrees with GE (also on SSD).

This seem to be fixed in @drewnoakes private updates, but that adds a lot of other changes too, implemented in a different way in GE master. See e.g.: 4085c6ed3a5354a3d6d70ded0d05008454fb7497

Steps to reproduce

• Several worktrees
• make changes in the trees to get slower time (to see slowdown more clearly)
• refresh

Did this work in previous version of GitExtensions?

OK before #12927

Diagnostics

No response