[TODO] Connect gameplay to new is_done() in planner

[kfu02]

Pull request: #1911

Link to TODO, or file number/line: path_target_planner.cpp:line 61

The is_done() methods in gameplay are not connected to the is_done() calls in the planner, so there is essentially a worse version of the same code in gameplay.

Gameplay should be connected to planner is_dones to avoid this weird quirk (which may involve more gameplay changes than I'd like).