Fix theme/skin-related CSS artefacts

[Q-intessence]

Description:
Environment : develop
Version : v0.2.1
Test case ID(s) : Navigation main menu test folder items
Test execution type(s) : Automation and Exploratory

Observation(s):
During automation testing the following concerns were picked up on the menu navigation:

• Switching to different themes (darkly & united) other than the default:
  • When selecting a sub menu item the text & highlighted colours are the same (Screenshot: nav_menu)
  • When concatenating the main menu then the text & highlighted colours are the same ( Screenshot: nav_menu_2)
• On the article pages:
  • Roles label/badge text and background colours are the same (Screenshot: article _roles)
    The above row items is making the text invisible.

Recommendation(s):
Discussion points we need consider in managing this issue:

• As we offer those themes as options in the scss file we need to add overrides
• Document the behaviour under the theming section

Attachements:
Screemshots.zip