Sync and blank state DB can produce errors

[daneryl]

Sync feature uses "_id" to match synced documents, when blank state is left not updated it can happen that there is a mismatch in "_id" for some documents, this happens because when blank state is not updated to the latest migration, the migrations are run and produce different _ids an easy example are the translations and this is why we had this kind of errors when trying to sync:

 "json": {
  "error": "E11000 duplicate key error collection: TENANT.translationsV2 index: language_1_key_1_context.id_1 dup key: { language: \"en\", key: \"% of sentences above threshold\", context.id: \"System\" }",
  "logLevel": "error",
  "prettyMessage": "E11000 duplicate key error collection: TENANT.translationsV2 index: language_1_key_1_context.id_1 dup key: { language: \"en\", key: \"% of sentences above threshold\", context.id: \"System\" }",
  "requestId": 7304
 },

the two instances have the same document but with different _ids, sync understands this as a different document but translations has a different unique _id set.

A workaround for this is to delete all translations from the target DB and let sync recreate the translations.

i did update the blank state to lower the chance of this happening in the near future.