The vendor was renamed from `wrm` to `werkraummedia`.
And the namespace vendor was renamed from `Wrm` to `WerkraumMedia`.
That way all references to PHP classes as well as the package name
itself need to be adjusted.
Add new record type partner.
This can be something like a media partner or something else.
Allow an event to have zero or more partner.
Add necessary files and models with relations.
Relates: #8092
