Rename BadRequestException to BadJsonRequestException.
Adjust ParamConv#supports() so PHP-Parser doesn't trip.

Adjust ParamConv#supports() so PHP-Parser doesn't trip during
extraction of translations.
Verify various DTO properties are strings.
Send DTOs directly to API services.

Don't wrap in superfluous commands.
Enable Mockery PHPUnit test listener.
Throw BadJsonRequestException when string errors > 0.
Move violation string mapping into BadJsonRequestException.
Test JsonConvertibleParamConverter.