Duplicate login, unauthorised and static pages

SignInBanner.tsx, UnauthorisedBanner.tsx and Static pages 'help' and 'feedback' need fleshing out to look at least similar to iar/frontend's versions.

added to epic &1 (closed)

added workflowSprint Ready label

added workflowIn Progress label and removed workflowSprint Ready label

mentioned in merge request !6 (merged)

added workflowReview Required label and removed workflowIn Progress label

closed via merge request !6 (merged)

mentioned in commit 37b65171

added workflowDone label and removed workflowReview Required label