Harmonise prefixes across ontology files

[l-emele]

Description of the issue

Not all ontology files contain the same set of prefixes. For example, dct is used in oeo.omn, but not in the module files.

Ideas of solution

Harmonise prefixes across files

Workflow checklist

• [ ] I discussed the issue with someone else than me before working on a solution
• [ ] I already read the latest version of the workflow for this repository
• [ ] The goal of this ontology is clear to me

I am aware that

• [ ] every entry in the ontology should have a definition
• [ ] classes should arise from concepts rather than from words

[l-emele]

Only a "nice to have" and not strictly necessary. Therefore removed from the major release 2.0.0.

[stap-m]

I am wondering whether all files should have harmonized prefixes or if we should check that only prefixes are set that are used?!

[l-emele]

only prefixes are set that are used

That is imho fine, too.

[stap-m]

Prefixes of the modules seem already harmonized. oeo.omn contains some more prefixes, though. However, there seem to exist predifined prefixes in owl and Manchester Syntax that cannot be changed. Therefore, I am hesitating to touch them.