Support internal HTTPS for WYSIWYG

[Steve-Mcl]

closes #1473

Description

• Checks RED.settings.requireHttps and switches the URL scheme to "https://"
• Also, if RED.settings.https is "something", apply an HTTPS agent too
  • (this bit i am not 100% sure about - might be just as well to apply the agent regardless of RED.settings.https) - lets see how it goes, it solves the OPs current issue)

Related Issue(s)

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

[Steve-Mcl]

after further consideration, I am closing this in favour of a new PR (incoming) change based off the wysiwyg work in #1469 which had to change axios promise chain to async await.

This is to both avoid having a merge conflict AND the fact I was not checking the right thing to determined a HTTPS scheme was required. In short, Node-RED listens on HTTPS when RED.settings.https is set to "something" not the presence of the flag requireHttps