Refactor: agency links

[thekaveman]

Part of #1520

The eligibility:unverified view uses the agency links construct. They also show up in two other views:

• core:help
• enrollment:retry

In eligibility and enrollment, we assume an agency has been selected by the user.

For core:help, the user may navigate there before selecting an agency, so we show all "agency links" for active agencies.

This PR moves the variation and content to a new template field: TransitAgency.links_template, referencing an includes file specific for the agency. The include is used explicitly where it is needed in templates.

This PR removes unused TransitAgency fields as well as deleting the Button.agency_contact_links() viewmodel helper.

[angela-tran]

I think the removal of viewmodel helper code in this PR looks great!

A separate thing I'm thinking about is that by moving the fields from TransitAgency into the templates, it's not as easy for a non-developer to update that information from an admin interface - it would instead require a code change in a template. This came from me thinking about the documentation for configuring a new transit agency. The tradeoff I guess is between being able to customize what shows up in an agency's links vs. saying every agency should show the same info which we can then edit in the database.

[thekaveman]

....it's not as easy for a non-developer to update that information from an admin interface

The tradeoff I guess is between being able to customize what shows up in an agency's links vs. saying every agency should show the same info which we can then edit in the database.

This is a good point. Alternative idea:

• Keep the info_url and phone fields, drop the template field for now
• Update the context_processor, render all agency links the same using context
• Later we can override the template if we need to

Basically just removing the viewmodel layer, but still using the normal context and default rendering template.

[angela-tran]

Alternative idea:

• Keep the info_url and phone fields, drop the template field for now
• Update the context_processor, render all agency links the same using context
• Later we can override the template if we need to

Basically just removing the viewmodel layer, but still using the normal context and default rendering template.

This sounds good to me 👍

[angela-tran]

Looks good!