Clean BaseValidator class code

Change boolean to enum
Remove unnecessary variables
Add JavaScriptUtil

Added JavaScriptUtil with method that converts a Java string to JavaScript
string with quotes.
Add tests for BackboneFieldTypeConverterManager
Restructure classes in frameworks package

Restructured package structure to match better the structure of other
packages:
Renamed FieldTypeConvertermanager to BaseFieldTypeConverterManager
Moved BaseFieldTypeConverterManager to frameworks.base package
Moved FieldTypeConverterManager to frameworks package