GetBranchTextStyle branch color.

adding candidate here which isn't present in the commands package because we need to actually go through the commits to get this info.

also adding this.

keeping these here as individual constants in case later on people want the old tree shape.

keeping these here as individual constants in case later on people want the old tree shape.

keeping these here as individual constants in case later on people want the old tree shape.

keeping these here as individual constants in case later on people want the old tree shape.

similar to the git_commands.BisectStatus but more gui-focused.