Catalyst Signed Docs endpoints simple integration test

[Mr-Leshiy]

Summary

Need to setup a separate earthly target to run a simple integration test case for Catalyst Signed Docs endpoints

Description

• make a a new test-signed-docs earthly target, similar how its done for test-postgres.
• inside that target you need to setup a event-db, cat-gateway running
• run a hurl ./catalyst-voices/catalyst-gateway/tests/api_tests/api_tests/signed_document.hurl script.

You will also need to modify signed_document.hurl with providing a RBAC token.
When running a cat-gateway setup environment var RBAC_OFF: True.