User defined health check interval

[Steve-Mcl]

Description

allow health poll interval to be set via user setting

NOTES:

• Can be approved any time, but should only be merged once all related PRs are approved:
  • Implement health check interval user setting flowfuse#3716
  • Add support for user set health check interval driver-localfs#124
  • Add support for user set health check interval driver-docker#92
  • Add support for user set health check interval driver-k8s#150

Adds tests:

  Launcher
    ✔ should create a new launcher
    health check
      ✔ has a default value
      ✔ can be set by user
      ✔ cannot be less than 1 second

Related Issue(s)

#227

TODO

• tests

Checklist

• I have read the contribution guidelines
• Suitable unit/system level tests have been added and they pass
• Documentation has been updated
  • Upgrade instructions
  • Configuration details
  • Concepts
• Changes flowforge.yml?
  • Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production

Labels

• Backport needed? -> add the backport label
• Includes a DB migration? -> add the area:migration label

[knolleary]

We can merge this PR - but the individual driver PRs can be rejected as we don't need to spread the logic out to them all - see FlowFuse/flowfuse#3578 (comment)