add non-OAuth providers

[ebagdasa]

Some providers might not use OAuth (e.g. on-device sensors, SQL-db, non-OAuth endpoints, etc) and we need to establish a way to allow Ancile to protect the data obtained from this sources.

1. We can create fetch_fucnctions that will be able to do any type of the call to DP, Rest, etc
2. Allow creation of the non-OAuth provider and assignment of corresponding policies.