Add Basic Authentication support to OpenMRS backend server

[icrc-fdeniger]

Currently only OpenID Connect can be used to log into OpenMRS Backend preventing community users from testing the Android application on the OpenMRS Demo Server at https://dev3.openmrs.org/.

The login process needs to be updated to also allow basic authentication. A new property auth.method should be introduced to let implementers choose the authentication method.

This property will be added to the file local.properties.default for documentation purposes and then in the developer's local.properties file for testing these new options.

• if auth.method is set to openid (the default value), the current authentication process using OpenID Connect will be used.
• if auth.method is set to basic, users will need to log in with a username and password (a new login page will need to be developed for this). If there are more than 5 failed login attempts, the system should enforce a 5-minute wait before allowing another attempt. These credentials (username/password) will be saved for XY hours ( this value will be configurable in a property)

To enable the Android application to work with the OpenMRS Demo Server, the following properties should be configured:

auth.method=basic
fhir_base_url=https://dev3.openmrs.org/openmrs/ws/fhir2/R4/
openmrs_rest_url=https://dev3.openmrs.org/openmrs/ws/rest/v1/
check_server_url=https://dev3.openmrs.org/openmrs/ws/rest/v1/session

Acceptance criteria

• The new auth.method property must function as described above.
• The README and setup documentation should be updated to reflect this new option.

Additional context

• See the current setup in docker-compose.yml using Keycloak as the identity provider.
• Authentication resources: https://github.com/icrc/openmrs-android-fhir/tree/main/core/src/main/java/org/openmrs/android/fhir/auth
• Basic Auth: https://github.com/google/android-fhir/blob/master/engine/src/main/java/com/google/android/fhir/sync/HttpAuthenticator.kt
• PR on google https://github.com/google/android-fhir/pull/2474