e2e-test: add data explorer editor action bar test

[midleman]

Summary

Adding test coverage for the editor action bar in data explorer view. Test verifies that following behaviors:

• split editor
• open new window
• display left/right
• note: sorting is already handled in other test

for the following scenarios:

• load data frame via variables pane (r script)
• load data frame via variables pane (python script)
• open parquet file via duck db
• open csv file via duck db

QA Notes

🟡 New test is tagged to run on all platforms in this PR.

@:editor-action-bar @:win @:web

[github-actions]

E2E Tests 🚀
This PR will run tests tagged with: @:critical @:editor-action-bar @:win @:web

^{readme  valid tags}

[midleman]

FYI. this test isn't new. it just moved (and renamed) and I forgot to use git mv. apologies!