feat: Add query.setHint() to support sql hint as inline comment in select queries (#3365)

* feat: Add query.setHint() to support sql hint as inline comment in select queries

This is for ORM queries only.

An ORM query like:

    new QCustomer()
      .setHint("FirstRows")
      .select(QCustomer.Alias.id, QCustomer.Alias.name)
      .findList();

Produces SQL that includes the hint as an inline comment like:

  select /*+ FirstRows */ t0.id, t0.name
  from customer t0

* Fix test QOrderTest

ebean-querybean/src/main/java/io/ebean/typequery/TQRootBean.java

@@ -912,6 +912,17 @@ public abstract class TQRootBean<T, R> {
     return root;
   }
 
+  /**
+   * Set a SQL query hint.
+   * <p>
+   * This results in an inline comment that immediately follows
+   * after the select keyword in the form: {@code /*+ hint *\/ }
+   */
+  public R setHint(String hint) {
+    query.setHint(hint);
+    return root;
+  }
+
   /**
    * Set the profile location.
    * <p>

ebean-querybean/src/test/java/org/querytest/QOrderTest.java

@@ -79,6 +79,19 @@ class QOrderTest {
     DB.delete(customer);
   }
 
+  @Test
+  void hint() {
+    LoggedSql.start();
+    new QCustomer()
+      .setHint("FirstRows")
+      .select(QCustomer.Alias.id, QCustomer.Alias.name)
+      .findList();
+
+    List<String> sql = LoggedSql.stop();
+    assertThat(sql).hasSize(1);
+    assertThat(sql.get(0)).contains("select /*+ FirstRows */ /* QOrderTest.hint */ t0.id, t0.name from be_customer t0");
+  }
+
   @Test
   void fetchQueryWithBatch() {
     LoggedSql.start();
@@ -159,8 +172,7 @@ class QOrderTest {
 
   @Test
   void viaFetchGraph_withNested_fetchQuery() {
-
-    DB.getDefault();
+    DB.cacheManager().clearAll();
     LoggedSql.start();
 
     final Order found = new QOrder()
@@ -181,8 +193,7 @@ class QOrderTest {
 
   @Test
   void viaFetchGraph_withNested_fetchCache() {
-
-    DB.getDefault();
+    DB.cacheManager().clearAll();
 
     // ensure the customer is loaded in the L2 cache
     new QCustomer().id.eq(customer.getId()).findOne();