[PublicAsset] JMAP specs for JMAP PublicAsset

[Arsnael]

Write specifications for JMAP PublicAsset extensions that allows users to store public assets that can be used to show on mail signatures.

• New capability object "com:linagora:params:public:assets". The object contains a quota for public assets per user: publicAssetTotalSize -> could be configurable via jmap.properties. Defaults to 20MB?

• PublicAsset object properties:

  • id (serverSet)
  • publicURI (serverSet)
  • size (serverSet)
  • blobId
  • identityIds: Id[]|null, default to null

• PublicURI: Needs a public JMAP route, that could be served following this pattern: {jmap_endpoint}/publicAsset/{accountId}/{assetId}

• JMAP get method, example => https://github.com/linagora/tmail-backend/issues/1042

• JMAP/set create method, example => https://github.com/linagora/tmail-backend/issues/1048

• JMAP /set update emthod, example => https://github.com/linagora/tmail-backend/issues/1050

• JMAP /set destroy method, example => https://github.com/linagora/tmail-backend/issues/1049

[Arsnael]

Need contentType right?

[Arsnael]

https://github.com/linagora/tmail-backend/pull/1056