Cleanup editor-site-launch

[razvanpapadopol]

Task Details

Latest mention in p58i-dox-p2#comment-56299

Cleanup editor Launch related code:

• [ ] ETK editor-site-launch folder (#75037)
• [ ] ETK typings (#75037)
• [ ] ETK common data-stores (#74551)
• [ ] editor_site_launch backend function - 29596-pb (including the exPlat code)
• [x] Focused Launch e2e tests
• [ ] Remove also AnchorFM launch flow from editor (see p1621965288224700/1621458244.077600-slack-C0202PMUXLJ) and its support code in ETK and backend (29596-pb)

Related to

53109;

follow up of https://github.com/Automattic/wp-calypso/pull/53115

[simison]

We will likely return to launch flow btw, just the button needs new placement.