Fix Marble verification with Coordinator root certificate

[thomasten]

External apps should be able to verify connections to Marbles by either the Coordinator root certificate or the Coordinator intermediate certificate (docs). For this to work, the Marble's certificate chain must include the Coordinator intermediate certificate, not the Marble Root certificate. This chain is verifiable by any of (i) Coordinator Root, (ii) Coordinator Intermediate, (iii) Marble Root.

Proposed changes

• Add an integration test that covers (i) and (ii) [(iii) already covered by multiple tests where test marble client connects to test marble server]
• Replace Marble Root with Coordinator Intermediate in Marble cert chain to fix (i)

[netlify]

✅ Deploy Preview for marblerun-docs canceled.

Name	Link
🔨 Latest commit	7076f3f
🔍 Latest deploy log	https://app.netlify.com/sites/marblerun-docs/deploys/6775c2401fda160008d0eee3