Swagger improvements

[joaoduarte19]

Some enhancements have been added to swagger middleware:

• Entities will be mapped in the definitions section. Issue Add section definition in the Swagger file #289. This feature is still in its early stages, many improvements can still be made.
• Added DefaultValue parameter to MVCSwagParamAttribute to enter default value of parameter. Issue Add Default parameters to swagger #291
• Added EnumValues parameter to MVCSwagParamAttribute to pass a list of possible values to the parameter. Issue Enum parameters #292
• The paths display in swagger has been changed to be sorted by tags. Issue Sorting endpoints #305