UML Plugin: Fix top-level uses statement being ignored

[nkhancock]

When rendering YANG modules with a 'uses' statement at the module level, such as can be found the YANG module openconfig-telemetry@2018-11-21, the top-level uses statement is ignored. This pull request fixes this issue.

The following examples illustrate what has been fixed.

The following YANG data models were used to test this fix:

test-groupings

module test-groupings {
  namespace "http://www.adtran.com/ns/yang/test-groupings";
  prefix tst-grp;

  revision 2024-03-11 {
    description
      "Initial revision.";
    reference
      "None.";
  }

  grouping grouping-1 {
    description
      "A grouping with a top-level non-interior data node.";
    leaf a-top-level-leaf-in-a-grouping {
      type string;
      description
        "Bla bla bla.";
    }
  }

  grouping grouping-2 {
    description
      "A grouping with a top-level interior data node.";
    container a-top-level-container {
      leaf a-leaf-within-a-top-level-container-in-a-grouping {
        type string;
        description
          "Bla bla bla.";
      }
    }
  }
}

test-uses-top-level

module test-uses-top-level {
  namespace "http://www.adtran.com/ns/yang/test-uses-top-level";
  prefix tst-uses-top;

  import test-groupings {
    prefix tst-grp;
  }

  revision 2024-03-11 {
    description
      "Initial revision.";
    reference
      "None.";
  }

  uses tst-grp:grouping-1;
  uses tst-grp:grouping-2;

}

Example 1: UML option --uml-inline-groupings not used

Before the fix:

After the fix:

Example 2: UML option --uml-inline-groupings used

Before the fix:

After the fix: