Auto merge of #23368 - gterzian:clean_up_navigation, r=asajeffrey

Clean-up navigation

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1. Navigation as a result of following a hyperlink should be done in a task: https://html.spec.whatwg.org/multipage/links.html#following-hyperlinks:dom-manipulation-task-source
2. The javascript url navigation should also be done in a task: https://html.spec.whatwg.org/multipage/browsing-the-web.html#navigating-across-documents:dom-manipulation-task-source
3. In `window.load_url`, it seems there is no need to send a message to the script-thread(the entirety of `load_url` should instead be done in a task when appropriate), so we can just do that last part "sync" by calling a method on the script, which will send a message to the constellation(for the parallel navigation steps), or queue task(for the JS navigation), as appropriate.
4. Separate the "normal" navigation flow from the handling of "navigate an iframe" message from constellation, since doing everything in one method as was previously done with `handle_navigate`, is confusing.

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- [ ] `./mach test-tidy` does not report any errors
- [ ] These changes fix #___ (GitHub issue number if applicable)

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1 files changed, 2 insertions, 2 deletions

diff --git a/components/webdriver_server/lib.rs b/components/webdriver_server/lib.rs
index de9e285037f..4df9e0d56b6 100644
--- a/components/webdriver_server/lib.rs
+++ b/components/webdriver_server/lib.rs
@@ -30,7 +30,7 @@ use script_traits::webdriver_msg::{LoadStatus, WebDriverCookieError, WebDriverFr
 use script_traits::webdriver_msg::{
     WebDriverJSError, WebDriverJSResult, WebDriverJSValue, WebDriverScriptCommand,
 };
-use script_traits::{ConstellationMsg, LoadData, WebDriverCommandMsg};
+use script_traits::{ConstellationMsg, LoadData, LoadOrigin, WebDriverCommandMsg};
 use serde::de::{Deserialize, Deserializer, MapAccess, Visitor};
 use serde::ser::{Serialize, Serializer};
 use serde_json::{json, Value};
@@ -593,7 +593,7 @@ impl Handler {
 
         let (sender, receiver) = ipc::channel().unwrap();
 
-        let load_data = LoadData::new(url, None, None, None);
+        let load_data = LoadData::new(LoadOrigin::WebDriver, url, None, None, None);
         let cmd_msg =
             WebDriverCommandMsg::LoadUrl(top_level_browsing_context_id, load_data, sender.clone());
         self.constellation_chan