Adding early version of unfinished schema for v4

[glenrobson]

Checking the new action runs.

[coveralls]

coverage: 76.16% (-1.1%) from 77.306%
when pulling 1e9fe6e on v4
into 11ef58d on main.

[glenrobson]

Questions:

• Should langauge in TextualBody be an array? It is in AnnotationBody
• Should all AnnotationBodies have an id?
• uc05 low and high filesizes are the same...

[glenrobson]

Update schema to match decisions in:

https://github.com/IIIF/api/pull/2427/changes

[glenrobson]

Can a look at be only a URI:

http://localhost:4000/api/presentation/4.0/model/#lookAt

or does it have to be an object with a type Annotationa and ID

[glenrobson]

Need to add action to API repo and check it works but I think this is almost done.