Provide Czech translation of SKOS

[ledsoft]

TermIt is based on SKOS. However, we do not have Czech translation of SKOS properties and classes. This means asset history view lacks attribute names that would corresponds to the labels we use in the UI. For example, in the following snippet:

skos:broader should corresponds to Nadřazené pojmy attribute in the term detail UI.

I think we should try to provide Czech translation for SKOS, add it to the initial data imported into the repository on installation so that the TermIt UI is more consistent.