Adding optional page argument to all_collections endpoint.

[cbarton4]

Related Issue(s):

• /collections only returns 100 collections, and should be paginated #65

Description:
Adds an optional "page" argument for all_collections endpoint.

PR Checklist:

• Code is formatted and linted (run pre-commit run --all-files)
• Tests pass (run make test)
• Documentation has been updated to reflect changes, if applicable, and docs build successfully (run make docs)
• Changes are added to the changelog

[jonhealy1]

Hi @cbarton4 can you run pre-commit run --all-files? The gh actions are throwing some minor linting errors. Thanks!

[cbarton4]

Apologies, missed that in the first go-around.

[philvarner]

I would prefer if this used the same search_after mechanism that item pagination does and that there be a "next" link in the collection response to get the next page of results, rather than a client just having to "know" that they need to add the page parameter.

Page should be fast enough with a relatively small number of collections (e.g., not millions), but I think there should be a next link so that clients can use that for pagination rather than hard-coding the use of page, which we may change in the future.

[cbarton4]

That's fair. This is here if we want it in, and our local will likely use this in the short term. I'll look into adding a "next" link when I have time to revisit this, hopefully in the November timeframe.

[jonhealy1]

There is now a pt to finish this work here: #164