feat(onboarding-templates): create actions from within the iframe

[raquelmsmith]

Problem

For #23065

Now that we have an iframe to work with an a UI for the variables, we need to communicate with the iFrame to set up the actions, and set them as the template variables.

Changes

It works!!

Screen.Recording.2024-09-09.at.1.48.36.PM.mov

• Show elements when selecting from site
• Set action name from template
• Create action without form (form is attached to toolbar, which we hide)
• Let people say if they want to include the element text, href, and page url
• Relay newly created action info back to template variable thing
• Show action info in template form
• Handle duplicately-named actions
• Fix dashboard creation not working
• Make sure people can use this if they haven't ingested any snippet events (they can set custom event names and, in a coming PR, use page URL)
  • 

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Does this work well for both Cloud and self-hosted?

How did you test this code?

[github-actions]

Size Change: +2.35 kB (+0.21%)

Total Size: 1.1 MB

Filename	Size	Change
frontend/dist/toolbar.js	1.1 MB	+2.35 kB (+0.21%)

_{compressed-size-action}

[posthog-bot]

📸 UI snapshots have been updated

2 snapshot changes in total. 0 added, 2 modified, 0 deleted:

• chromium: 0 added, 2 modified, 0 deleted (wasn't pushed!)
• webkit: 0 added, 0 modified, 0 deleted

Triggered by this commit.

👉 Review this PR's diff of snapshots.

[zlwaterfield]

Wow, this is really awesome. Nice work. :) The code looks good, although I don't understand much of it.

I can't get my ingestion to work locally ATM, so I didn't test. I can test again tomorrow once I get the ingestion working.