chore: add liveliness and readiness probes for nodes

## Overview
Due to bugs #172, it makes sense to add proper liveliness checks for all the nodes that are run.

## Implementation
Containers to add to:
* Validator container: run `status` cmd or rest call to `/status` endpoint
* exposer container
* registry container

> Note: Need to run smoke tests against the system to make sure there is no regression in performance of the repo

Start by locating the container and Helm definitions for the validator, exposer, and registry, then inspect the validator's `status` command and `/status` endpoint. Add the requested liveness and readiness checks and run smoke tests against the system to verify there is no performance regression.

Written by the indexing model from the issue text.