Adds schema relations between entities

[danigargar]

Add MediaRelaySet required relations to Carrier, DdiProvider and Company. Add ApplicationServerSet required relation to Company.

Type Of Change

• [ ] Small bug fix
• [x] New feature or enhancement
• [ ] Breaking change

Checklist:

• [x] Commits are named and have tag following commit rules
• [x] Commits are split per component (schema, portal/platform, kamusers, agis, ..)
• [x] Changes have been tested locally
• [ ] Fixes an existing issue (Fixes #XXXX)
• [ ] Upport from existing Pull request #XXXX

Description