core/merge: Moved docs can never equal any dst doc
core/merge: Moved docs can never equal any dst doc

  When merging a document move in PouchDB, we request 2 records from the
  database:
  - any record with the given source path
  - any record with the given destination path

  If a record with the destination path exists then we check if we can
  perform an overwriting move. If not, we were verifying if that
  document was the same as the one being moved but it does make sense as
  a document can only exist at one path at a time.

  Therefore, we remove this check (and don't break any test in the
  process) and will trigger a conflict resolution when trying to move a
  document to a path where another document exists and we can't
  overwrite it.

cozy-labs/cozy-desktop,cozy-labs/cozy-desktop,cozy-labs/cozy-desktop,cozy-labs/cozy-desktop