Tweak VisitInput to match "established" Glossary terms

[akademy]

"Visit" has been deprecated (in Diamond's GraphQL) for - the more enigmatic - "Instrument Session Id". For reasons.

It should be (at the least) possible to change the label of the current Visit Input to something else, to allow the name change.

However... perhaps the name of the component should be switched over too. In this case it may be better to have two components based on the same underlining code, so as not to break current use of VisitInput - but this is a goodopportunity to refactor the component into more useful parts, usable in future input boxes.

Thoughts?

[VictoriaBeilsten-Edmands]

We should stay up to date with the latest terminology. Is Instrument Session Id set for the foreseeable future? Are UAS considering experiment?

[akademy]

As far as our GraphQL goes, it's "Instrument Session" - the session service so far hides any UAS terminology. But I guess we could make it configurable, but default to IS...

[akademy]

It's also come to my attention that the proposal code isn't necessary i.e. the proposal number is already unique, so it'd be useful if we could somehow not require it...