Integrate OpenSRP with External App via In-App Intent - Optional Additional Features

[qiarie]

This is currently out of scope but we may later explore (for elearning context only)

• Authentication integration with Keycloak,
• Passing authenticated user context between the apps.
• Deep-linking directly into specific application modules,
• Surfacing MoH-hosted training completion status inside OpenSRP.

For now, this issue focuses strictly on enabling access via an intent.

Originally posted by @roywanyaga in #3817