Allow for web UI logo/text to be overridden

[astb01]

It would be nice if in the docker compose we could override the logo text and if possible provide our own logo, such as:

environment:

   WEB-UI-SITE-NAME: 'foo'
   WEB-UI-LOGO: /mounted-path-to-img

[astb01]

This is useful when you want to differentiate between multiple instances running in environments for testing purposes, ie TEST, UAT etc