Epic: Allow ManagedControlPlane to order ManagedControlPlane

[GenosseOtt]

User request

As a platform owner I want to excite and empower all my teams with MCPs.
I want to handover pre-configured MCPs for the differrent teams, all orchestrated and defined in code using one ManagedControLPlane (aka. Umbrella MCP!)

User story

Phase 1: Guide using Flux

• Educate in guide how ServiceAccount can be created to use with Flux
  Result: Engineers do not like this one! Stop investing!

Phase 1: Guide using GH Action

• Guide: How to order from Onboarding API via GitHub Action #82
  Result: Engineers do not like this one! Stop investing - full focus on Provider!

Phase 2: POC Provider using Short lived token

• Onboarding Provider POC using Shortlived token #67

Phase 3: Bring Provider to MCP with proper Authentication

• Establish Trust Onboarding API <-> Provider from ManagedControlPlane #68

Phase 4: Empower Platform Admins

• Community validation
• Roll out

Out of scope

#155

Automated version, allow anyone to

• enable Provider in their MCP from ReleaseChannel
• Automatically establish trust between Onboarding API and ManagedControlPlane