DBController refactoring (#1228)

* Moves transform to MongoTransform

- Adds ACL query injection in MongoTransform

* Removes adaptiveCollection from DatabaseController

- All collections manipulations are now handled by a DBController
- Adds optional flags to configure an unsafe databaseController for direct
  access
- Adds ability to configure RestWrite with multiple writes
- Moves some transfirmations to MongoTransform as they output specific code

* Renames Unsafe to WithoutValidation

src/Adapters/Storage/Mongo/MongoSchemaCollection.js

@@ -1,5 +1,6 @@
 
 import MongoCollection from './MongoCollection';
+import * as transform from './MongoTransform';
 
 function mongoFieldToParseSchemaField(type) {
   if (type[0] === '*') {
@@ -200,6 +201,10 @@ class MongoSchemaCollection {
     update = {'$set': update};
     return this.upsertSchema(className, query, update);
   }
+
+  get transform() {
+    return transform;
+  }
 }
 
 // Exported for testing reasons and because we haven't moved all mongo schema format