Split run methods into smaller blocks of code.

[Christian-B]

ref:
The run methods have grown to be too long and complex

SpiNNFrontEndCommon/spinn_front_end_common/interface/abstract_spinnaker_base.py

Line 538 in 2855f41

def __run(self, run_time: Optional[float], sync_time: float):

SpiNNFrontEndCommon/spinn_front_end_common/interface/interface_functions/application_runner.py

Line 74 in 2855f41

def run_app(

A better approach is to split these into three different methods for each run type

• run timed probably also run timed looped
• run forever
• run until stopped

the have these call support methods where they share behaviour