* add basic e2e testing setup

* adjust execute test step name

* test sidebar chat icon, add testing class

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* add sidebar snapshot

* test chat sidepanel, extend helper class

* adjust welcome message test, add snapshot

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* adjust naming

* removeempty line

* move ui-tests to packages/jupyter-ai/

* update e2e ci workflow for ui-tests folder move

* update ui-tests folder location for yarn.lock hash

* run lint locally

* Add "Update Playwright Snapshots" CI workflow

* change if clause

* specify npm client

* remove report and artifact specifiers

* Update README.md to have correct commands and folders

* update e2e/integration test README

* Add Integration / E2E testing section to the docs

* update wording of docs on snapshots

* Ignore all non-linux snapshots

* Update packages/jupyter-ai/ui-tests/README.md

Co-authored-by: Piyush Jain <[email protected]>

* remove cd command that would return users back to root

* remove cd ../../../

* Remove repeating setup instructions

* Add suggestion to generate snapshots before the 1st run

* remove unnecessary link anchor

* remove rudimentary jlpm build

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Piyush Jain <[email protected]>