Export configuration to include signing namespace and key name

Closes #3

See merge request gaia-x/data-infrastructure-federation-services/tsa/infohub!3

Before this change the infohub service created VP itself and just
used the signer for acquiring a VP proof. With the new Signer endpoint
which can create VP from raw JSON data, the complexity in the export
decreased, because the infohub must not create a VP itself - VP
creation and VP proofs are completely delegated to the Signer service.

Issue token from OAuth server and pass it along with HTTP requests

Closes #4

See merge request gaia-x/data-infrastructure-federation-services/tsa/infohub!2

Add cache TTL attribute in export configuration

Closes #1

See merge request gaia-x/data-infrastructure-federation-services/tsa/infohub!1

Migrate vereign to gaiax gitlab

See merge request gaiax/tsa-migrate/infohub!1

Default context for VC/VP to allow arbitrary JSON in credential subject

Closes #15

See merge request !15

Remove subject id from the VC

See merge request !14

Subject id must be represented in specific format, while currently
it's arbitrarily contructed from policy group/name/version
and causes problems with VC/VP signatures.

Verify proofs by calling the signer service

Closes #14

See merge request !13

Before this commit, the infohub was verifying VP proofs by itself.
Now this is delegated to the signer service for consistency, as the
signer service can act as both producer and verifier of proofs.

Expose prometheus metrics

Closes #12

See merge request !11

Replace LICENSE

See merge request !12

Add basic service documentation to README.md

Closes #4

See merge request !10

Resolve DID:WEB verification methods for proofs

Closes #11

See merge request !9

update

See merge request !8

update

See merge request !7

HTTP endpoint to import trusted data

Closes #7

See merge request !6