Build/Test Tools: Add end-to-end (e2e) tests for edit posts page.
Adds e2e tests for 'Edit Posts':
- No posts found
- Shows a single post after publishing
- Edit existing post via Edit button
- Quick edit existing post via Quick Edit button
- Delete post
Props isabel_brison, azaozz, hellofromTonya, justinahinon, talldanwp, youknowriad.
Fixes #49507.