Clean-up and normalize RSpec and Rubocop

[mjgiarlo]

Why was this change made? 🤔

Consistency and clarity. This reduces the Rubocop noise in the codebase and in the test output. Current output:

$ rake
Running RuboCop...
Inspecting 17 files
.................

17 files inspected, no offenses detected
/media/mjg/44aee93d-a48a-4ad3-ae90-4b084bb04b69/rvm/rubies/ruby-3.1.2/bin/ruby -I/media/mjg/44aee93d-a48a-4ad3-ae90-4b084bb04b69/rvm/gems/ruby-3.1.2@folio_client/gems/rspec-support-3.12.0/lib:/media/mjg/44aee93d-a48a-4ad3-ae90-4b084bb04b69/rvm/gems/ruby-3.1.2@folio_client/gems/rspec-core-3.12.1/lib /media/mjg/44aee93d-a48a-4ad3-ae90-4b084bb04b69/rvm/gems/ruby-3.1.2@folio_client/gems/rspec-core-3.12.1/exe/rspec --pattern spec/\*\*\{,/\*/\*\*\}/\*_spec.rb
..................................

Finished in 1.35 seconds (files took 1.71 seconds to load)
34 examples, 0 failures

Coverage report generated for RSpec to /home/mjg/workspace/sul-dlss/folio_client/coverage. 153 / 159 LOC (96.23%) covered.

Includes:

• Remove documentation format from RSpec config (only five of our many codebases do this, and with the change here, that is down to four)
• Bump RSpec/MultipleExpectations cop max to 3 since FolioClient has tests where having 2-3 expectations is more readable than the alternative
• Add missing/new RSpec/Capybara cops
• Regenerate Rubocop todos (now zero :tada:)
• Reorganize Rakefile per our usual conventions

How was this change tested? 🤨

CI