fix: make probes configurable

[karlderkaefer]

this change gives the user the option to overwrite values for probes for example

helm template . --set probes.readiness.timeout=5s -s templates/solaceStatefulSet.yaml | grep -A 6 "readinessProbe:"
        readinessProbe:
          exec:
            command:
            - /mnt/disks/solace/readiness_check.sh
          initialDelaySeconds: 30
          periodSeconds: 5
          timeout: 5s

closes #137

[karlderkaefer]

@bczoma could you take a look?

[bczoma]

@karlderkaefer thanks for the proposal. Solace is adding this to the list of upcoming features and will include it in a release, together with documentation.