Metadata for pluggable elements

[cmdcolin]

Currently we have parts of our code that may raw list the raw "class name" of different pluggable elements

This includes the:

1. List of view types when session is empty
2. List of adapter types and track types when adding tracks
3. List of display types when toggling display types for a track

the canonical internal name may be familiar to devs and advanced users but inexperienced users may benefit from more human readable names

[garrettjstevens]

A description may also be nice as well

[rbuels]

Core metadata:

• displayName - used in menus if present
• description - used by UI as tooltips or help text

but pluggable elements can add whatever they want in addition to these of course