[FHIR Road Map]: Fhir-web keycloak theme support

[peterMuriuki]

Issue Context?

Add keycloak themes for opensrp-2-web client.

Issue Implemetation details?

N/A

Issue Acceptance criteria?

When someone goes to login, they should see a bespoke fhir-web theme. Previous keyclok theme done lives here: https://github.com/opensrp/opensrp-keycloak-themes/blob/main/images/default/login.png

FHIR resources to be used?

No response

Relevant Information

No response