feat/vue_processing_save - clean up logic of building save request and response handling
@dmytro.rudnyk - please have a look
Main points of this MR:
- simplify code in terms of count of "if", lines of code, ability to read what is there
- do NOT sent to server unneeded "collection" property with request: sever does not need it, client can handle responses without it
- when try to build request - use collectionInfo (metadata) instead of store.collections (data) to iterate over collections