[WebDriver] Fully implement "switch to (parent) frame" (#37685)

1. Separate the handling of ["switch to parent
frame"](https://w3c.github.io/webdriver/#switch-to-parent-frame) from
the rest as the processing is a bit different
2. Implement "Select frame by 16-bits numbered ID" for ["switch to
frame"](https://w3c.github.io/webdriver/#switch-to-frame)
3. Implement other missing steps

Testing: All WebDriver Conformance test with new passing cases

---------

Signed-off-by: Euclid Ye <yezhizhenjiakang@gmail.com>

components/script/script_thread.rs

@@ -2494,6 +2494,9 @@ impl ScriptThread {
                     can_gc,
                 )
             },
+            WebDriverScriptCommand::GetParentFrameId(reply) => {
+                webdriver_handlers::handle_get_parent_frame_id(&documents, pipeline_id, reply)
+            },
             WebDriverScriptCommand::GetBrowsingContextId(webdriver_frame_id, reply) => {
                 webdriver_handlers::handle_get_browsing_context_id(
                     &documents,