feat(tournament): add group match creation and enhance match handling

- Implemented createGroupMatches function to generate matches for existing groups without altering group assignments.
- Updated resetMatches function to support optional class filtering when resetting group matches.
- Enhanced frontend components to filter and display group matches based on selected class, improving user experience.
- Adjusted tournament results display to reflect accurate match statistics, including wins and losses.

backend/routes/tournamentRoutes.js

@@ -8,6 +8,7 @@ import {
   setModus,
   createGroups,
   fillGroups,
+  createGroupMatches,
   getGroups,
   getTournament,
   getTournamentMatches,
@@ -58,6 +59,7 @@ router.post('/matches/reset', authenticate, resetMatches);
 router.put('/groups', authenticate, createGroups);
 router.post('/groups/create', authenticate, createGroupsPerClass);
 router.post('/groups', authenticate, fillGroups);
+router.post('/matches/create', authenticate, createGroupMatches);
 router.get('/groups', authenticate, getGroups);
 router.post('/match/result', authenticate, addMatchResult);
 router.delete('/match/result', authenticate, deleteMatchResult);