Refactor graph creation in all tests into new internal MakeTestGraph trait

This large refactor allows future re-use of the existing tests for `FrozenGraph`, which does not implement `GraphTopologyAddition`, but instead has to convert from a different graph which does.

- Fix tests for `GraphTopologyDeletion` hard-coding Graph instead of using the trait.
- Fix some tests silently depending on macro call site uses.
- Change `GraphTopologyAddition` tests to use `Default::default` instead of `new`.
- Add new tests for `GraphTopology::vertex_map` and `edge_map` that also depend on `GraphTopologyAddition`, removing these dependencies from the existing tests.
- Add new test macro `graph_topology_addition_deletion_tests` for tests that need deletion and addition.

src/models/graph.rs

@@ -378,13 +378,18 @@ impl GraphTopologyDeletion for Graph {
 }
 
 #[cfg(test)]
-mod tests {
-    use super::*;
+mod trait_tests {
+    use super::Graph;
 
-    crate::graph_topology_test_fixtures!(Graph);
     crate::graph_topology_tests!(Graph);
     crate::graph_topology_addition_tests!(Graph);
     crate::graph_topology_deletion_tests!(Graph);
+    crate::graph_topology_addition_deletion_tests!(Graph);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
 
     #[test]
     fn incident_vertices_paired_index() {