Ease the transition from pythonSoftIOC to FastCS

[coretl]

FastCS has no interactive terminal for EPICS IOCs. People are used to this from pythonSoftIOC so we need to make it easy to:

1. Do a dbl of all the records in the IOC
2. Poke around at the internals to see why something is failing

It seems like 1. is easiest to do from the outside with some commandline script that gets the PVI structure and prints a nice tree of PVs.

To do 2. it is probably best to go down the route of VSCode remote debugging.

This issue is a spike to investigate both of these things and propose potential solutions for both.

Acceptance Criteria

• Solutions to both of the above investigated, discussed, agreed and tickets made to implement

[GDYendell]

Prototyped here: https://github.com/GDYendell/fastcs2/blob/main/src/fastcs2/control_system.py#L44

[GDYendell]

Superceded by #140 and #179 ?