wrote query to sum up the number of watchlist entries for an exercise id, then wrote the test and merged development into my branch

This accepts data from the updated backend
(from the previous commit) but does not display
any of the new metadata yet.

This is not tested with search results, because I could
not obtain search results locally. Suggestions on the
home page work, but no results are shown in /search

refactored statistics so that they are loaded by the statistics service and then resolved the collections bug

disabled button when not logged in, allowed get request for number of likes and has liked for not logged in user

resolved error with fontsawesome that it worked with yarn start but not with mvnw as mvnw uses npm and the package.lock had the wrong fontawesome version but the yarn had

This is done as to reduce the file size
and complexity of the exercise-details component.

Let the mailto link actually include
the email address instead of consisting
only of "mailto:"

added GitlabService.java to offer basic gitlab api functionalities like check if repo exists etc. , added check in StatisticsResource to avoid people sending get requests with IDs which not exist and therefore create lots of trash entities