refactor: replace TSLint with ESLint

src/environments/environment.prod.ts

@@ -12,6 +12,7 @@
  * You should have received a copy of the GNU General Public License along with
  * this program. If not, see <https://www.gnu.org/licenses/>.
  */
+// eslint-disable-next-line unicorn/prevent-abbreviations
 export const environment = {
   backend_url: 'https://mobile.server.uni-frankfurt.de',
   backend_version: '2.0.0',