Migrate extensions and services from annex to registry

[kirschbombe]

Preview: https://preview.iiif.io/api/annex-migration-services/registry/services/

This draft PR is the start of migrating the annex/services content to registry/services. So far this:

• copies the GeoJSON section over to registry per Update API Annex doc references to GeoJSON inclusion, given IIIF NavPlace Extension?  #2019
• adds a note that GeoJSON as a service is for v2 and for v3 use navPlace per Update API Annex doc references to GeoJSON inclusion, given IIIF NavPlace Extension?  #2019
• adds a new column to the services table to differentiate between presi 2/3 (not sure if we want that)
• copies physdim section over to registry
• copies the service names table over to registry
• replaces icon definitions with reference to icon table in https://iiif.io/api/presentation/3.0/#a-summary-of-property-requirements
• adds SearchService2 to service names table per add SearchService2 to Linking to External Services documentation and Prezi3 documentation #2051

Some questions/comments:

• do we want to have columns for presi 2 and 3 in the table?
• migrating physdim from annex to registry changes the context path. For now, I updated the paths in the migrated text and made a copy of the physdim folder which I placed in the "registry/services" folder, leaving the original in "annex/services" folder as well
• physdim has a note about adding a confidence label - is that something to discuss?
• Editor's agreed that it would be good for physdim to get TRC review (next deadline in 9th Feb.)
• I also found this issue discussing physdim as an extension instead of service: Document Physical Dimensions extension #1358

[tomcrane]

Icons in the table could maybe reference https://iiif.io/api/presentation/3.0/#a-summary-of-property-requirements rather than redefine the symbols?

[glenrobson]

How do you get to the webannotation registry part? Should it be linked from the api/index.md file?