DCGW: Clarify roles/permissions

## Definition of done
- Custom teams table for common personas on https://developer.konghq.com/konnect-platform/teams-and-roles/#dev-portal-custom-teams
- All DCGW how tos have required roles listed in prereq
- Consider if DCGW reference pages could also display required roles as like a green note?

## Information
Feedback: https://docs.google.com/document/d/1QtYLFaR4hlwtyrE_hF_RL2BAwalFpC7rgAoYrEKasiA/edit?tab=t.0

## Due date (optional)

## Size
L

Start with the linked teams-and-roles page and the Google Docs feedback, then inventory the DCGW how-to and reference pages affected. Done means common personas are documented, every how-to lists required roles in its prerequisites, and the reference-page role note decision is addressed.

Written by the indexing model from the issue text.