John conroy/select datasets on search CAT-984

[john-conroy]

Summary

• Allows users to select all shown results on the search pages. Selections are not reset when results change.

Screenshots/Video

Checklist

• [x] Code follows the project's coding standards
  • [x] Lint checks pass locally
  • [x] New CHANGELOG-your-feature-name-here.md is present in the root directory, describing the change(s) in full sentences.
• [x] Unit tests covering the new feature have been added
• [x] All existing tests pass
• [x] Any relevant documentation in JIRA/Confluence has been updated to reflect the new feature
• [x] Any new functionalities have appropriate analytics functionalities added

Additional Notes

@tsliaw The ticket didn't include a tooltip for deselecting all of the results. Does 'Reset all selections.' work?