Add scale to CrawlOut (#1487)

Fixes #1486 

`scale` is already saved in the crawl but needed to be added to
`CrawlOut`.

backend/btrixcloud/models.py

@@ -609,6 +609,7 @@ class CrawlOut(BaseMongoModel):
     stopping: Optional[bool]
     manual: Optional[bool]
     cid_rev: Optional[int]
+    scale: Optional[conint(ge=1, le=MAX_CRAWL_SCALE)]  # type: ignore
 
     storageQuotaReached: Optional[bool]
     execMinutesQuotaReached: Optional[bool]