Formation Deprecation - Core import swap

[micahchiang]

Description

The last remaining step that needs to be done in order to remove the Formation package from vets-website is to replace the import path for core.scss.

This Formation stylesheet has a counterpart in css-library that brings imports the necessary styles vets-website relies on to maintain visual parity.

We need to replace the vets-website import path from Formation to css-library, ensure we've done visual regression testing in several high traffic applications, static pages, and the injected header, and then merge a PR into vets-website for this change.

Considerations

• css-library pull request that includes necessary updates to stylesheets in order to maintain parity with what is in production.
• vets-website pull request that updates the import path and adds grid classes to shame.scss
• For now, grid classes need to continue to be maintained manually. We can either leave them in shame.scss for the time being, or bring them into css-library and import them through core. Either way, the classes need to exist as they currently do because they do not rely on !Important, unlike utility classes.
• Testing needs to be done thoroughly on this ticket. Even though the lines changed are relatively small, the impact on vets-website is potentially high. Screenshots of each thing tested need to be attached to the vets-website PR listed above.
• At a minimum we should test: Profile, MHV Secure Messaging, Combined Debt Portal, Claims Status, content-build hub pages, at least one form application
• Content-build will inherit changes locally from vets-website as long as both repos are running locally at the same time.

Tasks

• Local testing with verdaccio, attach screenshots for applications tested
• Merge css-library PR and publish a new version so we can spin up a review instance in vets-website
• Review instance testing in vets-website to corroborate local diff testing
• Merge vets-website pull request

Acceptance Criteria

• Above tasks have been completed

[caw310]

Hey team! Please add your planning poker estimate with Zenhub @Andrew565 @ataker @harshil1793 @it-harrison @jamigibbs @micahchiang @powellkerry @rmessina1010 @rsmithadhoc