WIP: Cypress tests for the Facets feature

[felipeelia]

Description of the Change

This PR adds cypress tests related to the Facets feature

• If feature is activated, user should see “ElasticPress - Facet” widget in dashboard.
• If user adds the Facet widget, it should render the items of the selected taxonomy in the widget
• If user adds the Facet widget and the length of the taxonomy is greater than 15, it should render an input search, and the items of the selected taxonomy
• If user adds a category called “New York” and assign a post to it, it should be possible to type for “New Y” and find the term
• If user adds two Facet widgets and the length of the selected taxonomy is greater than 15, the user should be able to search in both widgets independently
• If user visits a paginated facet, clicking on a new facet should reset pagination

Related to #2614

Changelog Entry

Added: e2e tests for the Facets feature.

Credits

Props @felipeelia