[feat]: add the ability to filter by group when fetching merge requests paginated

Author: aakashnshah

pom.xml

@@ -5,7 +5,7 @@
 	<groupId>org.gitlab4j</groupId>
 	<artifactId>gitlab4j-api-cortex</artifactId>
 	<packaging>jar</packaging>
-	<version>6.0.3</version>
+	<version>6.0.4</version>
 	<name>GitLab4J-API - GitLab API Java Client</name>
 	<description>GitLab4J-API (gitlab4j-api) provides a full featured Java client library for working with GitLab repositories and servers via the GitLab REST API.</description>
 	<url>https://github.com/gitlab4j/gitlab4j-api</url>

src/main/java/org/gitlab4j/api/MergeRequestApi.java

@@ -71,6 +71,8 @@ public List<MergeRequest> getMergeRequests(MergeRequestFilter filter, int page,
             }
 
             response = get(Response.Status.OK, queryParams, "projects", filter.getProjectId(), "merge_requests");
+        } else if (filter != null && filter.getGroupId() != null && filter.getGroupId().intValue() > 0) {
+            response = get(Response.Status.OK, queryParams, "groups", filter.getGroupId(), "merge_requests");
         } else {
             response = get(Response.Status.OK, queryParams, "merge_requests");
         }