fix(mongo): fail update/delete when 0 documents match

[ZhuchkaTriplesix]

Summary

• `updateOne` / `replaceOne` / `deleteOne` throw when `nMatched` / `nRemoved` is 0 (wrong `_id` type, deleted doc).
• Inspector and JSON editor already catch that as Save Failed. Identical `$set` (`nModified == 0`) still counts as a match.

Closes #776

Test plan

• Save a Mongo field after deleting the document elsewhere → inspector shows the 0-match error, not success
• JSON editor Save with a stale `_id` → Failed to save, not Document saved successfully
• Save the same value again (`nModified == 0`) still succeeds
• Delete of an already-deleted document errors instead of silently succeeding