Error list for assets in Editor

[aclysma]

Need to come up with a solution for aggregating data errors and presenting them to the user in the editor.

• Should be easy to insert these into assets. Perhaps a verify callback? Possibly should handle being generated at runtime (i.e. play in editor) too. Maybe this could hook HELIUM_VERIFY, or we have a new macro that's similar i.e. HELIUM_VERIFY_DATA
• Should be able to jump to the problematic object/asset and field

Could be some small overlap with the channels-based logging task. Perhaps we have a special channel or log level threshold to show up in the errors window in the editor?