DISH AIV: Prototype interface with SPFC and Band 2 Reciver for DISH Maintenance GUI

Relates to SP-3742 and TAIV-788.

The Dish AIV team need a GUI to expose a number of low-level device attributes for SPFC maintenance and installation. This GUI has come with a short time frame and so pragmatic solutions are required.

A full specification is given in: TAIV-788

This feature seeks to select a technology upon which to build a Dish AIV maintenance GUI and the generate a prototype exposing the (some off the) required attributes with an initial focus (PI20) is on "Services" (Helium and Vacuum) and B2 interfaces. See slides 2,4,7 and 8 of https://docs.google.com/presentation/d/1Wk4B2QptrrVa9MXKWUrapmX7_CRaJPrApMDOWhC6kIE/edit?usp=drive_web