Send Hold/Recall requests to ILLiad

[thatbudakguy]

Closes #1889

• Support sending Hold/Recall requests to ILLiad
• Convert the Scan request job into a generic ILLiad request job
• Extract an Illiadable concern for mixing into Requests
• Make HoldRecall Illiadable and create feature flag

shared_configs PRs to turn it on:
https://github.com/sul-dlss/shared_configs/pull/2087
https://github.com/sul-dlss/shared_configs/pull/2088
https://github.com/sul-dlss/shared_configs/pull/2089

[jcoyne]

Using modules that override methods on the class they are mixed into, isn't the easiet to read. Is there a reason this is needed? I see that HoldRecall#submit! already calls SubmitIlliadRequestJob can we modify Scan#submit to call SubmitIlliadRequestJob directly?

even better might be to convert this module to a new class (e.g. IlliadRequest) and have a method on the "Illiadable" requests like #illiad_request. I think there is value in separating the concept of "The user made a request" and "We made this ILL request to fulfull the users request"

[thatbudakguy]

I'm fine just not including this method in the mixin – I figured if you mixed in Illiadable it'd be because you want to submit the request via ILLiad, but in the case of scans we also want to do something else, so it's fine to just be explicit instead.

[thatbudakguy]

Updated to remove the method and make Scan#submit! explicitly call the illiad job