Merge remote-tracking branch 'origin/8-umsetzung-der-graphischen-oberflache-von-gernot' into 8-umsetzung-der-graphischen-oberflache-von-gernot

These errors were ignored by the partial
recompilation of "npm start".
Make sure to recompile to verify that code
actually compiles.

This button does not fit with the metadata
and took away valuable space in its previous
location.

Replace the hard coded paragraph in a search result's
detail view with data taken from the search result.

Add the fields required to recreate the original
design with mocked data.

Exchange hard-coded strings for jhiTranslate values.

Metadata still needs to be modified.

Adjust number of cards per row to the screen's width.

Wrap cards into container to achieve spacing
between the cards.

Let all cards in a row have the height of the tallest
card.

IDs need to be refactored further, since
for each search result the same IDs are used.

Previously, the course details always showed data
of the first result. Now, clicking "Open course"
will display the results for the correct course.

Currently the detail view for a result shows
the information of the first result in the list.