Run the e2e smtp servers only when configured to do so

[cstns]

Description

• added a new isEmailEnabled cypress command that checks if email is configured
• skipping tests that need email config when not configured locally
• running smtp containers only if configured in the yml file

Smtp containers will run only if the following configuration is present in the etc/flowforge.local.yml file:

...
e2e:
  email:
    os:
      enabled: false
      debug: true
      smtp:
        host: localhost
        port: 1025
        web_port: 8025
        secure: false
    ee:
      enabled: true
      debug: true
      smtp:
        host: localhost
        port: 1026
        web_port: 8026
        secure: false
...

This allows a granular approach to testing

Related Issue(s)

docs update FlowFuse/website#3188

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

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

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.31%. Comparing base (cb4d14f) to head (14edfe1).
Report is 7 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5457   +/-   ##
=======================================
  Coverage   77.31%   77.31%           
=======================================
  Files         350      350           
  Lines       16583    16583           
  Branches     3865     3865           
=======================================
  Hits        12821    12821           
  Misses       3762     3762           

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