Added Class Validation and Error Handling

[jlozion026]

-[x] Create Unmodelized Error
-[x] Added Class-Validator
-[X] Remove Stacktrace
-[x] Modify error return object
-[x] Created EmailAlreadyExist Decorator

[PaoGon]

resovel merge conflict

  git checkout master
  git pull

  git checkout <branch mo>
  git merge master

  #ayusin mo merge conflict

  git add .
  git commit -m "..."
  git push origin <branch mo>

@jlozion026