[AMORO-3065] Optimizing rest api efficiency for table detail (#3260)

For table detail we'll retrive detail info  from underlying table, before the change
there will be two call to the catalog when loading the table: 1) check whether the database exists,
2) load the table for the detail info. After the change, the first call to catalog has been removed,
and use the second call to check if the table exists.

amoro-common/src/main/java/org/apache/amoro/CommonUnifiedCatalog.java

@@ -122,10 +122,6 @@ public void dropDatabase(String database) {
 
   @Override
   public AmoroTable<?> loadTable(String database, String table) {
-    if (!databaseExists(database)) {
-      throw new NoSuchDatabaseException("Database: " + database + " does not exist.");
-    }
-
     return formatCatalogAsOrder(
             TableFormat.MIXED_HIVE,
             TableFormat.MIXED_ICEBERG,