[Feature Request]: Add manual (non-API based) process to interact with app for end-2-end testing

[averissimo]

Feature description

Problem

{shinytest2} e2e tests are currently created around AppDriver$set_input that will make the necessary changes via javascript: Shiny.setInput function (within {chromote} session).

Current approach successfully tests the app, but it lacks the real interactions that users have with the app, that is:

• Is the input being used visible / existing in the UI
• Can the user interact with it

Idea

• Add to API functions that find <input> elements and can modify value (triggering observe callbacks in R)
  • methods for filter panel interaction to modify filters (alternative to set_active_filter_selection)
  • methods to change encoding panel (alternative to set_module_input)

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