Rust: Make Element.toString non-recursive

Author: hvitved

rust/ql/lib/codeql/rust/elements/internal/ModuleImpl.qll

@@ -24,6 +24,6 @@ module Impl {
    * ```
    */
   class Module extends Generated::Module {
-    override string toStringImpl() { result = "mod " + this.getName() }
+    override string toStringImpl() { result = "mod " + this.getName().getText() }
   }
 }

rust/ql/lib/codeql/rust/elements/internal/UseImpl.qll

@@ -19,6 +19,6 @@ module Impl {
    * ```
    */
   class Use extends Generated::Use {
-    override string toStringImpl() { result = "use " + this.getUseTree() }
+    override string toStringImpl() { result = "use " + this.getUseTree().toAbbreviatedString() }
   }
 }