[Issue #2144] e2e tests for clear/select all filters and fix nested filter bug

[doug-s-nava]

Summary

Fixes #2144

Time to review: 15 mins

Changes proposed

• adds e2e tests for "select all" and "clear all" filter functionality, including for agencies / nested filters
• fixes bugs with nested filters that showed incorrect selected filter counts and did not correctly clear selected filters

Context for reviewers

Test steps

Observe bug

1. start the app on main
2. from the search page, click "select all" at the top level of the agencies filter
3. VALIDATE: the ui suggests that 39 items are selected, when only 21 are
4. open an expander to show nested filter options
5. click "select all" for the nested options
6. VALIDATE: top level search options are cleared when nested ones are selected
7. select a top level option
8. click "clear all" under nested section
9. VALIDATE: all options are cleared, not just nested ones

Validate fix

1. start the app on this branch
2. from the search page, click "select all" at the top level of the agencies filter
3. VALIDATE: the ui states that 21 items are selected
4. open an expander to show nested filter options
5. click "select all" for the nested options
6. VALIDATE: top level search options are not cleared
7. select a top level option
8. click "clear all" under nested section
9. VALIDATE: only nested options are cleared

Additional information

The filter components are still a bit of a mess, made a follow up ticket for some more cleanup work. #3331

[doug-s-nava]

these should probably be moved to a utils file, but getting them out of the component is a good first step. Saving bigger refactors for #3331

[acouch]

👍🏿