VCL_recv rework based on closed Magento 2 PR

[toonvd]

Description

This PR is a rework of the Magento VCL (the vcl_recv part) PR found here: https://github.com/magento/magento2/pull/36796/files

I left out 2 controversial changes:

• Removing the pass of /customer and /checkout Main reason for this is that, as a hoster (and support on Varnish issues), I see a lot of extensions that accidently remove cache disables. Without this part of the VCL, the result could be a disaster for merchants.
• Removing caching of authenticated GraphQL requests Though I understand the reasoning behind this (preventing cache variations), the same technique is used in the frontend. I have seen this work perfectly for one of our clients, so I am hesitant to remove something that seemed to be working

PRs for other subroutines will follow (probably weekly)

All credits go to @peterjaap and @ThijsFeryn, I am simpling slicing this up and removing controversial parts to get early approval.

Related Pull Requests

https://github.com/magento/magento2/pull/36796/files

Manual testing scenarios

• Load the new VCL
• Test if compression still works
• Test if restarts don't loop anymore
• Test purges without headers

Contribution checklist (*)

• [x] Pull request has a meaningful description of its purpose
• [x] All commits are accompanied by meaningful commit messages
• [x] All new or changed code is covered with unit/integration tests (if applicable)
• [x] README.md files for modified modules are updated and included in the pull request if any README.md predefined sections require an update
• [x] All automated tests passed successfully (all builds are green)

[peterjaap]

Thanks @toonvd, it's still on my todo list to make that Magento PR better, but time & priorities, so I'm excited to see you picking this up for MageOS! :)

[ThijsFeryn]

Looks good to me, thanks for the effort @toonvd