Formation Deprecation - Swap shared variable imports from Formation to CSS-Library

[micahchiang]

Description

The majority of applications individually import formation shared variables. These should be switched to css library using the import path:
@import '~@department-of-veterans-affairs/css-library/dist/tokens/css/variables.scss';

Considerations

• We'll need to make sure all shared variables imported in formation/shared-variables.scss are accounted for in css-library/variables.scss

Tasks

• Update the import for all applications that individually import shared variables from formation

Acceptance Criteria

• The above tasks have been completed

[caw310]

Duplicate of #3328