Resolve "Rename parser to namespace"

Description

Add new namespace type to replace the parser type. The system now requires a namespace to be initialized instead of the parser and name.

In several places the namespace is initialized to an empty string, but there are actually two different cases where this happens: 1) global variables that are not system dependent; 2) places where the code is not yet aware that we might have different namespaces. I'm not sure if case 1) should be handle like it is at the moment. Maybe it would be better to make the namespace optional when calling the parser. As for case 2), this mostly happen in the utilities, but I'm not sure how namespaces should be handled there.

Checklist

• I have checked that my code follows the Octopus coding standards
• I have added tests for all the new features added in this request.

Closes #212 (closed)