Update traefik router hardcoded priorities

[YuryHrytsuk]

What do these changes do?

• Update traefik router hardcoded priorities according to the rules below
  • 1 --> 3
  • 2 --> 6
  • 3 --> 9
  • 10 --> 12
• Remove unnecessary priority from adminpanels and registry service

This PR introduces some space in-between the routers which we can use to flexibly add new routers. It shouldn't break existing priority hierarchy since numbers <13 are still below any other non-hardcoded priorities.

Remarks for future:

• Whenever introducing some priorities to traefik routers (or other similar cases) one better to make them spacious to retain flexibility. This case is a good example why "spacious" approach makes sense

Related issue/s

• Add fallback nginx to serve "something went wrong" #218

Related PR/s

• ♻️ Update traefik router hardcoded priorities osparc-simcore#7141
• Add fallback nginx to serve "something went wrong" #950

Checklist

• I tested and it works

[mrnicegyu11]

I agree w.r.t. making the space of traefik priorities spacious, look good from my side