Add optional status array unpacking

[GDYendell]

Currently status arrays (i.e. arrays that are read-only) are left as a single parameter and formatted as a string. This is useful in cases where the list will change at at runtime, e.g. the the error parameter of a frame processor. In cases where the array is static, it could be useful to unpack the array into individually indexed attributes, for example so that PV clients can read individual integers rather than a string that needs parsing.

The formatting as a string (here) is done too early to be able to change the logic because we don't even know what plugins are loaded at this point. I think the best thing do is search for array OdinParameters in _process_parameters and replace them with individual parameters. There should be a function (suggest unpack_status_arrays) in odin_fastcs.util that takes a list[OdinParameter] and a (list of uris) (list[list[str]]) to search for and replace. It will insert the new indexed OdinParameters into the list and remove the original. Then in a specific OdinAdapterController this function can be called with whatever parameter uris it wants to be split.

This can be tested in FrameProcessorController._process_parameters to split ["status", "plugins", "names"], although possibly we don't actually want it on this. Let's see. Or it could be tested on xspress if a controller is made for that, this was the original use case.