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

repaired UI display of types and languages as it was again hidden behind the exercise cards on small screens

In the escape sequence "·" there was unicode
code point 0332 (UTF-8 cc b2), which is a
"combining low line". I think this does not belong
in there.

The exercise metadata component is only rendered
when it gets a value which is not null and has
a length of at least one (either string or array).
If it gets a value which is translated before it
is being passed, the result will be something of
the form "translation-not-found[...]", which has
a length of at least one, so it is rendered.
To prevent this, check if a value is set before
translating it.

They were replaced with exercise-metadata-item.

The goal of this component is abstracting away
the difference between metadata fields which are
strings and the ones which are arrays of strings.

This removes the <br> tags which were
previously inserted after every five elements.
Line breaks should be handled dynamically
by the browser.

This makes displaying metadata of an exercise
less verbose. Styling is a bit lacking as of now.

Restructure metadata translations of lists
to make declarations more concise.

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