Display availability statements when relevant

[matt-bernhardt]

This integrates the recently-added AlmaSru model with the UI, restoring the availability statements for users to see. This involves:

1. Defining a lookup route /almasru which invokes the lookup method
2. Adding a _trigger pattern on the Primo result partial that will invoke this lookup route when needed

In service of these goals, a few other changes get introduced:

3. The content loader stimulus controller gets added support for lazy loading, which gets activated by adding data-content-loader-lazy-loading-value="" to the tag which calls the controller.
4. The AlmaSru model gets its validation and extraction logic altered, so that there is an externally-callable valid_alma_id?() method. The UI leverages this to make sure we only ask for this lookup when the ID seems relevant (there's no way to know from just an identifier whether a record will actually have an availability block - but we can tell when a record comes from Alma).

Side effects:

• The guard clauses around this integration are a little inconsistent at the moment. I don't think any of the calculations are horribly inefficient, so I think it's probably fine - but I'd welcome some specific attention on this point.
• The "enabled?" method on AlmaSru gets renamed from .alma_sru_enabled? to just .enabled?
• I alphabetized the lookup routes in config/routes.rb

Developer

Accessibility

• ANDI or WAVE has been run in accordance to our guide.
• This PR contains no changes to the view layer.
• New issues flagged by ANDI or WAVE have been resolved.
• New issues flagged by ANDI or WAVE have been ticketed (link in the Pull Request details above).
• No new accessibility issues have been flagged.

New ENV

• All new ENV is documented in README.
• All new ENV has been added to Heroku Pipeline, Staging and Prod.
• ENV has not changed.

Approval beyond code review

• UXWS/stakeholder approval has been confirmed.
• UXWS/stakeholder review will be completed retroactively.
• UXWS/stakeholder review is not needed.

Additional context needed to review

Do searches in the review app (or when running locally), and watch the network traffic in your dev tools. You should see lazy-loading happening, and you should only see this happening for records with Alma docIDs. This should happen across tabs.

Code Reviewer

Code

• I have confirmed that the code works as intended.
• Any CodeClimate issues have been fixed or confirmed as
  added technical debt.

Documentation

• The commit message is clear and follows our guidelines
  (not just this pull request message).
• The documentation has been updated or is unnecessary.
• New dependencies are appropriate or there were no changes.

Testing

• There are appropriate tests covering any new functionality.
• No additional test coverage is required.

[coveralls]

Coverage Report for CI Build 27716939663

Coverage increased (+0.01%) to 98.415%

Details

• Coverage increased (+0.01%) from the base build.
• Patch coverage: 20 of 20 lines across 2 files are fully covered (100%).
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

---

Coverage Stats

Relevant Lines:	1514
Covered Lines:	1490
Line Coverage:	98.41%
Coverage Strength:	71.52 hits per line

---

💛 - Coveralls

[qltysh]

❌ 2 blocking issues (3 total)

Tool	Category	Rule	Count
rubocop	Lint	Method has too many lines. [16/10]	1	❌
rubocop	Style	Use underscores(_) as thousands separator and separate every 3 digits with them.	1	❌
qlty	Structure	Function with high complexity (count = 5): lookup	1

[qltysh]

Use underscores(_) as thousands separator and separate every 3 digits with them. [rubocop:Style/NumericLiterals]