chore: deployment startup ordering

[4ndrelim]

1. xtramcp backend needs to be started and ready before paperdebugger backend attempts connection. Currently, this is manually ensured. We can enforce an ordering with a startup gate by including in the initContainer of paperdebugger.
2. Add healthcheck node to check for xtramcp start-up before starting PD pod.

Additional:

• Propose to remove defaults for some secrets and allow backend processing logic to handle instead.

Future:
re-try logic for for more robust handling of connection re-try. This will also facilitate re-establishing connection during pod failures.

[4ndrelim]

@Junyi-99 oops sorry could you re-approve to unblock? the only change is the update of the image tag. Implemented health node on xtramcp's backend and used it for the deployment ordering. tested on dev server.

[Junyi-99]

@4ndrelim ok done