Visualize local branch heads in commits panel

We want to mark all local branch heads with a "*" in the local commits panel, to
make it easier to see how branches are stacked onto each other. In order to not
confuse users with "*" markers that they don't understand, do this only for the
case where users actually use stacked branches; those users are likely not going
to be confused by the display. This means we want to filter out a few branch
heads that shouldn't get the marker: the current branch, any main branch, and
any old branch that has been merged to master already.

pkg/gui/context/local_commits_context.go

@@ -42,6 +42,8 @@ func NewLocalCommitsContext(c *ContextCommon) *LocalCommitsContext {
 		return presentation.GetCommitListDisplayStrings(
 			c.Common,
 			c.Model().Commits,
+			c.Model().Branches,
+			c.Model().CheckedOutBranch,
 			c.State().GetRepoState().GetScreenMode() != types.SCREEN_NORMAL,
 			c.Modes().CherryPicking.SelectedShaSet(),
 			c.Modes().Diffing.Ref,