[FLINK-38239][oceanbase] Re-enable OceanBase CDC integration tests in CI with Docker image

- Remove @disabled annotations from OceanBase test classes
- Replace environment variable dependencies with obbinlog-ce:4.2.5-test container
- Add comprehensive e2e integration tests for oceanbase-cdc connector

Author: yuanoOo

flink-cdc-connect/flink-cdc-source-connectors/flink-connector-mysql-cdc/src/test/java/org/apache/flink/cdc/connectors/oceanbase/OceanBaseSourceTestBase.java

@@ -165,9 +165,10 @@ protected static void dropDatabase(String dbName) {
 
     protected static List<String> fetchRows(Iterator<Row> iter, int size) {
         List<String> rows = new ArrayList<>(size);
-        for (int i = 0; i < size; i++) {
+        while (size > 0 && iter.hasNext()) {
             Row row = iter.next();
             rows.add(row.toString());
+            size--;
         }
         return rows;
     }