feat(match2): make match2 behavior customizable for each project in lab

[ElectricalBoy]

Summary

Each project in the lab wiki has one root page and all content pages for a project are (grand)children of the root page.
This PR takes advantage of this structure and adds per-project entrypoints in lab match2, with the current lab match2 setup as a fallback.

How did you test this change?

preview with dev

[hjpalpha]

seems okayish

just make sure that we tell people that:

• there is no support at all for those kinds of modules (except for nuking them if they cause issues)
• if the project becomes an alpha wiki there is no guarantee we will port that version
  • if the quality is up to standards (or close to it) we would use it as a basis most likely though

[mbergen]

Do we expect these modules to be tracked via this repo?

[ElectricalBoy]

Do we expect these modules to be tracked via this repo?

no

[mbergen]

Do we expect these modules to be tracked via this repo?

no

That seems very much prone for errors (and thus conflicts) whenever base match modules are changed, potentially requiring adjustments of custom ones if we aren't aware of a bunch of them.

[ElectricalBoy]

That seems very much prone for errors (and thus conflicts) whenever base match modules are changed, potentially requiring adjustments of custom ones if we aren't aware of a bunch of them.

somewhat intended; this pr's goal is giving an option for lab people to be on the bleeding edge if they decide to
hence we would be telling them to proceed at their own risk and they will be getting no support from us whatsoever as mentioned in hjp's review

[mbergen]

As long as it's clear these aren't exactly supported, LGTM