Patch autosave associations to support conditional validations

[lostie]

What

For more details please read NOTE in config/initializers/01_autosave_association_patch.rb

Claim associations are autovalidated by default as long as they're defined. With this change, they're only validated if they're required for a specific step/stage or if they're being submitted through the API.

Ticket

Check your claim page fixes

Why

Rails models that accept nested attributes for some of its associations autosave and validate those associations by default.

What this means in effect is that, even though the application has its own stage/step validation setup for the claims model, as long as an association was previously set in another stage, when submitting data for another stage, that association will still be autosaved and validated. (This is noted more so when one of the stages is submitted as a draft with invalid data for one of the associations and other stage is then submitted with valid data but fails due to the previously submitted association being invalid, even though we're not at the step of validating that association).

How

• The claim model no longer has a default form_step, as that information is specifically related with the claim submission process only, and the form_step is now set only during that flow.
• Autosave associations in Rails was patched to evaluate the value set for validate: <value> as by default it just checks if is true or not. This way it allows us to control when these associations are actually validated, letting the validations classes behave as expected during the submission flow and only validate the data related with that particular stage. (NOTE: Obviously this patching will potentially have an impact on any future Rails updates)

Also, worth of note:

• Some of the fee factories, now detect if the associated fee type already exists instead of creating a brand new one. This was done mainly to avoid flakey tests and unexpected behaviours and should also helps making use of the seed data more reliably going forward.
• There's a known issue with the factories definition that needs to be addressed. The resolution is not part of this PR as this would take quite a lot of refactoring. In this PR, the previous behaviour (which was to create a claim with a default form_step was kept).

[colinbruce]

👍 LGTM