Guard against users without team edit accessing billing

[Pezmc]

Description

Fixes two issues:

• Prevents a request failed error when navigating to a team where a user does not have edit team access
• Blocks the /billing pages entirely from users without team edit access (previously just hidden in the UI)

Related Issue(s)

Fix #1845

Checklist

• I have read the contribution guidelines
• [-] Suitable unit/system level tests have been added and they pass - Not possible to easily test request is not being made
• [-] Documentation has been updated
  • Upgrade instructions
  • Configuration details
  • Concepts
• [-] Changes flowforge.yml?
  • Issue/PR raised on flowforge/helm to update ConfigMap Template
  • Issue/PR raised on flowforge/CloudProject to update values for Staging/Production

Labels

• Backport needed? -> add the backport label
• Includes a DB migration? -> add the area:migration label