Add proper recorder download pages

[andrewvc]

We currently release the synthetics recorder via github. We should move to proper download pages on elastic.co once we have code signing.

There's an open question around whether we align the recorder with stack releases. I'd propose that we do this simultaneously for the simple reason that customers won't have to worry about compatibility with the Elastic stack etc.

We should only do this once we have proper code signing etc.

• We need telemetry on the download
  • When it occurred
  • What version was downloaded
• The download location will need to be updated, so provide the new URL to:
  • Docs
  • Synthetics UI

CC @justinkambic @lucasfcosta @kyungeunni @paulb-elastic

[kyungeunni]

@justinkambic, @v1v, and I discussed this topic today and drafted up a plan for code signing, releasing, and publishing.

Here are the milestones we'd like to tackle one by one.

1. Build and release recorder from Jenkins on tag push (without signing)
2. Sign and notarise recorder for Mac and Windows
3. Publish recorders to elastic's artifacts storage and deprecated Github release

[kyungeunni]

We will follow instructions from the Release eng team.

• Update CI to push artifacts to designated storage
  • Pick a download URL that meets stats service criteria
• Request a download page by creating a ticket for web content team
  • Google doc of expected landing page

[kyungeunni]

This should be pushed to 8.8 as release-eng team doesn't have the bandwidth for 8.7 https://github.com/elastic/release-eng/issues/592#issuecomment-1384937790

[paulb-elastic]

@kyungeunni do you know if, when this is on the proper download location, we get the download statistics defined in the top description?

We'll also need a URL for the download location, as we need to update the docs and the Kibana UI (I've added to the main description).

[paulb-elastic]

Whilst the final download location is being created, we may need an intermediate location in GitHub (a specific MD page somewhere) that @drewpost is working on (so, a more curated page than the main releases page).

[paulb-elastic]

Moving to 8.9 as we have a plan b for GA

[paulb-elastic]

@drewpost moving to the backlog to pick up when you think we're likely to be able to get this set up