Investigate slow performance of page requests with lots of items

[cbeer]

E.g.:
https://requests-folio-dev.stanford.edu/requests/new?item_id=L284&origin=LANE-MED&origin_location=LANE-SAL3
https://requests-folio-dev.stanford.edu/requests/new?item_id=L13&origin=LANE-MED&origin_location=LANE-COR
https://requests-folio-dev.stanford.edu/requests/new?item_id=L17&origin=LANE-MED&origin_location=LANE-COR
https://requests-folio-dev.stanford.edu/requests/new?item_id=3248266&origin=SAL3&origin_location=PAGE-MP

Hopefully the -prod environment will speed up these requests, but we should do some due diligence and:

• see where the performance bottlenecks are,
• see if there are "easy" fixes we can make immediately, and
• create tickets for larger application re-work (e.g. async loading of holdings information)

[jcoyne]

For L284:

I, [2023-08-08T10:54:12.397376 #3495995]  INFO -- : [49276810-9203-4f07-b2d5-db3d745a2679] Processing by PagesController#new as HTML
I, [2023-08-08T10:54:12.397484 #3495995]  INFO -- : [49276810-9203-4f07-b2d5-db3d745a2679]   Parameters: {"item_id"=>"L284", "origin"=>"LANE-MED", "origin_location"=>"LANE-SAL3"}
...
I, [2023-08-08T10:54:46.030230 #3495995]  INFO -- : [49276810-9203-4f07-b2d5-db3d745a2679] Completed 200 OK in 33633ms (Views: 8909.2ms | ActiveRecord: 0.6ms | Allocations: 13773000)

The step that takes all the time is Request#pageable?

new_params = {"item_id"=>"L284", "origin"=>"LANE-MED", "origin_location"=>"LANE-SAL3"}
current_request = Request.new(new_params)
current_request.pageable?

The underlying cause of this is because the GraphQL client takes a long time (~33s) to return results:

 require 'benchmark'
puts Benchmark.measure { FolioGraphqlClient.new.instance(hrid: 'L284') }
  0.035882   0.008006   0.043888 ( 32.931976)
 => nil

[corylown]

• One fallback would be load the page right away, but show a loading widget.
• We should look to see if there are optimizations to be made in graphql.