Add file triggers and file meta data (#6344)

* added hint to aggregate

* added support for hint in query

* added else clause to aggregate

* fixed tests

* updated tests

* Add tests and clean up

* added beforeSaveFile and afterSaveFile triggers

* Add support for explain

* added some validation

* added support for metadata and tags

* tests?

* trying tests

* added tests

* fixed failing tests

* added some docs for fileObject

* updated hooks to use Parse.File

* added test for already saved file being returned in hook

* added beforeDeleteFile and afterDeleteFile hooks

* removed contentLength because it's already in the header

* added fileSize param to FileTriggerRequest

* added support for client side metadata and tags

* removed fit test

* removed unused import

* added loging to file triggers

* updated error message

* updated error message

* fixed tests

* fixed typos

* Update package.json

* fixed failing test

* fixed error message

* fixed failing tests (hopefully)

* TESTS!!!

* Update FilesAdapter.js

fixed comment

* added test for changing file name

* updated comments

Co-authored-by: Diamond Lewis <findlewis@gmail.com>

src/middlewares.js

@@ -114,6 +114,7 @@ export function handleParseHeaders(req, res, next) {
   }
 
   if (fileViaJSON) {
+    req.fileData = req.body.fileData;
     // We need to repopulate req.body with a buffer
     var base64 = req.body.base64;
     req.body = Buffer.from(base64, 'base64');