feat: add loc scheme

[iFergal]

Requires a new KERIA dev release before merging.

Allows signify controller to sign and submit a /loc/scheme reply message to authorise an endpoint it controls. Generally the signing hab is the eid but that could be different for multi-sig (mhab/ghab).

[kentbull]

Is the purpose of this for the controller to authorize new kinds of service endpoints for the agent of an AID?

[iFergal]

For the controller as it's signed at the edge. We have been using it for the indexer role for OOBI discovery, though from conversations with @lenkan that might need some revision.

[kentbull]

This will be a useful feature.

[kentbull]

@iFergal will you rebase this? I want to get this merged. This will be useful.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.53%. Comparing base (c9ea16d) to head (04269ec).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #305   +/-   ##
=======================================
  Coverage   97.53%   97.53%           
=======================================
  Files           1        1           
  Lines         324      324           
  Branches       24       24           
=======================================
  Hits          316      316           
  Misses          8        8           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[kentbull]

LGTM

[kentbull]

@lenkan will you review and approve this?