feat: Fully use protobuf, fix controller issues and cleanup (#305)

## Description
### First commit
Restructured protobuf schemas to make them easier to use across
languages, switched to using them in-place of JSON for signaling as
well, so there's no 2 different message formats flying about. Few new
message types to deal with clients and nestri-servers better (not final
format, may see changes still).

General cleanup of dead/unused code along some bug squashing and package
updates.

TODO for future commits:
- [x] Fix additional controllers not doing inputs (possibly needs
vimputti changes)
- [x] ~~Restructure relay protocols code a bit, to reduce bloatiness of
the currently single file for them, more code re-use.~~
- Gonna keep this PR somewhat manageable without poking more at relay..
- [x] ~~Try to fix issue where with multiple clients, static stream
content causes video to freeze until there's some movement.~~
- Was caused by server tuned profile being `throughput-performance`,
causing CPU latency to be too high.
- [x] Ponder the orb


### Second + third commit
Redid the controller polling handling and fixed multi-controller
handling in vimputti and nestri code sides. Remove some dead relay code
as well to clean up the protocol source file, we'll revisit the meshing
functionality later.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added software rendering option and MangoHud runtime config;
controller sessions now support reconnection and batched state updates
with persistent session IDs.

* **Bug Fixes**
* Restored previously-filtered NES-like gamepads so they connect
correctly.

* **Chores**
* Modernized dependencies and protobuf tooling, migrated to
protobuf-based messaging and streaming, and removed obsolete CUDA build
steps.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: DatCaptainHorse <DatCaptainHorse@users.noreply.github.com>

packages/server/src/nestrisink/mod.rs

@@ -18,7 +18,8 @@ impl NestriSignaller {
         nestri_conn: NestriConnection,
         wayland_src: Arc<gstreamer::Element>,
         controller_manager: Option<Arc<ControllerManager>>,
-        rumble_rx: Option<mpsc::Receiver<(u32, u16, u16, u16)>>,
+        rumble_rx: Option<mpsc::Receiver<(u32, u16, u16, u16, String)>>,
+        attach_rx: Option<mpsc::Receiver<crate::proto::proto::ProtoControllerAttach>>,
     ) -> Result<Self, Box<dyn std::error::Error>> {
         let obj: Self = glib::Object::new();
         obj.imp().set_stream_room(room);
@@ -30,6 +31,9 @@ impl NestriSignaller {
         if let Some(rumble_rx) = rumble_rx {
             obj.imp().set_rumble_rx(rumble_rx).await;
         }
+        if let Some(attach_rx) = attach_rx {
+            obj.imp().set_attach_rx(attach_rx).await;
+        }
         Ok(obj)
     }
 }