added some error codes as global variables

v0.5.33

feat: added some error codes as global variables

modified and renamed ErrFieldInvalidValue

v0.5.32

refactor: modified and renamed ErrFieldInvalidValue

added ErrInvalidRequestBody again

v0.5.31

fix: added ErrInvalidRequestBody again

solved some bugs

v0.5.30

fix: solved some bugs

I forgot to remove the HTTP status parameter from the interface...

v0.5.29

fix: I forgot to remove the HTTP status parameter from the interface...

added ErrorCode and HTTPStatus getters to RequestError interface

v0.5.28

refactor: added ErrorCode and HTTPStatus getters to RequestError inte…

added HandleError function to Handler interface

v0.5.27

feat: added HandleError function to Handler interface

added RequestError interface and its implementations

refactor: added RequestError interface and its implementations

* Added RequestError interface and its implementations (FieldError, HeaderError and ParameterError)
* Re-structured folders

modified FieldError's Error type

refactor: modified FieldError's Error type

* Modified FieldError's Error type
* It's Error(), not String()...

added missing String method to FieldError struct

v0.5.23

refactor: added missing String method to FieldError struct