Add dynamic creation for detector status parameters

[GDYendell]

In EigerController.connect()

• Get detector/.../status/keys
• Get for each parameter
• Then zip together the parameters names and the list of responses and do
  • Function to take `value_type' and return a FastCS type

    match type:
    case 'float':
    Float()
    ...

  • Function to create a FastCS attribute from that FastCS type and access_mode

    match mode:
    case 'r':
    AttrR(type, ...)
    ...

  • setattr(self, name, attr)

The EPICS backend should then create PVs for all of these parameters.