refactor: simplify UUID processing and standardize SchemaUtils usage

- Removed unnecessary UUID casting in repositories (`ExposedFunktionaerRepository`, `ExposedReiterRepository`, `ExposedVereinRepository`).
- Replaced `SchemaUtils.createMissingTablesAndColumns` with `SchemaUtils.create` in database configuration for consistency.

Signed-off-by: Stefan Mogeritsch <stefan.mo.co@gmail.com>

backend/services/masterdata/masterdata-service/src/main/kotlin/at/mocode/masterdata/service/config/MasterdataDatabaseConfiguration.kt

@@ -34,7 +34,7 @@ class MasterdataDatabaseConfiguration {
             // Database connection is already initialized by the gateway
             // Only initialize the schema for this service
             transaction {
-                SchemaUtils.createMissingTablesAndColumns(
+              SchemaUtils.create(
                     LandTable,
                     BundeslandTable,
                     AltersklasseTable,
@@ -90,7 +90,7 @@ class MasterdataTestDatabaseConfiguration {
 
             // Initialize database schema for tests
             transaction {
-                SchemaUtils.createMissingTablesAndColumns(
+              SchemaUtils.create(
                     LandTable,
                     BundeslandTable,
                     AltersklasseTable,