Use our own http server for the webdriver server (#44338)

Helps with: https://github.com/servo/servo/issues/38776. Reduces total
Servo crate count by 7 (977 -> 970).

This PR simply:
- Disables the `server` feature in the `webdriver` crate
- Vendors the implementation of the server from the `webdriver` crate
- Updates dependencies + fixes code to work with new versions

Unfortunately `webdriver` depends on `http` even with the `server`
feature disabled, so we still end up with duplicate versions of `http`.
But at least the duplicate `hyper` is eliminated. Future work could
change the implementation to e.g. move away from `warp` or similar.

Testing: WPT tests use webdriver, so this should be exercised heavily by
those tests.

---------

Signed-off-by: Nico Burns <nico@nicoburns.com>

deny.toml

@@ -153,13 +153,7 @@ skip = [
     "thiserror-impl",
 
     # duplicated by webdriver
-    "h2",
-    "headers",
-    "headers-core",
     "http",
-    "http-body",
-    "hyper",
-    "socket2",
 
     # duplicated by winit
     "block2",