Access Services Using API Key

[sekulicd]

Description:
Update calls to prem and internal services by adding relevant api-key to the Authorization header.

For prem-services: The Authorization header should contain service-specific api_key. Use this api to fetch service api key.
For internal services: The Authorization header should contain root api_key. This will be fetched on login.

Reference:
Please refer to the related premAI-io/prem-gateway#21 for further details.

@tiero @filopedraz @Janaka-Steph