JsonMention
This type can contain the following fields:
| field | type | info | 
|---|---|---|
| length | int | The length of the mention represented in the message. Seems to always be 1 but included here in case that changes. | 
| start | int | The number of characters in that the mention starts at. Note that due to a quirk of how signald encodes JSON, if this value is 0 (for example if the first character in the message is the mention) the field won’t show up. | 
| uuid | String | The UUID of the account being mentioned | 
- v0.JsonQuote.mentions
- v0.JsonDataMessage.mentions