script: Refactor channels in `ScriptThread` into receivers and senders (#34776)

Create two new data structures in the `script` crate to hold senders and
receiver:

- `ScriptThreadSenders`: holds all outgoing channels from the
  `ScriptThread` including a channel to the `ScriptThread` itself. The
  ultimate goal with this is to reduce duplication by giving a boxed
  version of this this to `Window`s.
- `ScriptThradReceivers`: holds all incoming channels to the
  `ScriptThread`. This isn't cloenable like the senders. This is used to
  abstract away `recv()` and `try_recv()` methods used to make the
  `ScriptThread` event loop easier to read.

In addition:

- The many duplicated `ScriptThread` self-senders for the `TaskManager`
  have been removed and, in general, a lot of boilerplate is removed as
  well.
- Visibilty of all methods affected by this change is changed to
  `pub(crate)` in order to take advantage of dead code detection. Some
  dead code produced from macros is removed.
- Some conversion code is refactord into implementations of the `From`
  trait.
- The names of channels uses a standard "sender" and "receiver" naming
  as well as trying to be descriptive of where they go in `ScriptThread`
  as well as `InitialScriptState`

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/components/script/task_source/websocket.rs b/components/script/task_source/websocket.rs
index 2d05067e28b..2ae11f99eb8 100644
--- a/components/script/task_source/websocket.rs
+++ b/components/script/task_source/websocket.rs
@@ -16,7 +16,7 @@ pub struct WebsocketTaskSource(
 
 impl Clone for WebsocketTaskSource {
     fn clone(&self) -> WebsocketTaskSource {
-        WebsocketTaskSource(self.0.clone(), self.1)
+        WebsocketTaskSource(self.0.as_boxed(), self.1)
     }
 }