Use Dataspace Authority DID to get catalog endpoint

[algattik]

Feature #58

Description

EDC catalog extension to get participants from registration service currently requires the URL of the registration service endpoint. Therefore that URL cannot be changed.

This URL is also present in the dataspace DID document. The EDC catalog extension should instead be configured with the dataspace DID URI, and periodically refresh the registration endpoint from the DID document.

This is symmetric to implementation for Registration Service command-line client #43

Acceptance Criteria

• Update catalog extension to get registration service endpoint from DID document.
• registration service endpoint is periodically refreshed (not only at application startup).

Tasks

Same as acceptance criteria.

[algattik]

Duplicate with #174