[management] fix extend call and move config to types (#3575)

This PR fixes configuration inconsistencies and updates the store engine type usage throughout the management code. Key changes include:
- Replacing outdated server.Config references with types.Config and updating related flag variables (e.g. types.MgmtConfigPath).
- Converting engine constants (SqliteStoreEngine, PostgresStoreEngine, MysqlStoreEngine) to use types.Engine for consistent type–safety.
- Adjusting various test and migration code paths to correctly reference the new configuration and engine types.

management/server/testdata/management.json

@@ -20,6 +20,11 @@
         "Secret": "c29tZV9wYXNzd29yZA==",
         "TimeBasedCredentials": true
     },
+    "Relay":{
+      "Addresses":["rel://test.com:3535"],
+      "CredentialsTTL":"2h",
+      "Secret":"netbird"
+  },
     "Signal": {
         "Proto": "http",
         "URI": "signal.netbird.io:10000",