[v10.4.3] Fixes

[ouziel-slama]

• fix NULL asset_events
• Add test for DISPENSE in mempool
• In the result of /v2:
  - use the github repo for the blueprint url
  - add the route routes: /v2/routes
• Add addresses argument for /v2/mempool/events route
• Add routes to get assets by issuer or owner
• Add prefixed data support to api.compose.unpack() function

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• Double-check the spelling and grammar of all strings, code comments, etc.
• Double-check that all code is deterministic that needs to be
• Add tests to cover any new or revised logic
• Ensure that the test suite passes
• Update the project release notes
• Update the project documentation, as appropriate, with a corresponding Pull Request in the Documentation repository