Add Avon green styling colours

[LukeParky]

DESCRIPTION OF PR:

Uses a forked version of TerriaMap from https://github.com/GeospatialResearch/TerriaMapOtakaro
This gives a different colour styling and a Kowhaiwhai design in the brand bar element.

EDIT: After discussions with Casey we made the call to change to a design that was not using designs that are strongly tied to UC

Developer Checklist

• Make code change
• Update tests
  • Update / create new tests
  • Ensure these tests have the expected behaviour
  • Test locally and ensure tests are passing
• Update documentation
  • Readme
  • Docstrings
  • Comments
  • Wiki

Reviewer Checklist

• Check new code for code smells
• Check new tests
  • Ensure adequate coverage
  • Check for code smells within tests
• Check if documentation needs updating
  • Readme
  • Docstrings
  • Comments
  • Wiki

[LukeParky]

@arpo-deer can you please give feedback on the design

[caseyli92]

As discussed, make sure all colours for everything are up to date and match :)

[caseyli92]

Great work :)