fix: Improve 2-way audio detection (#2293)

- For Frigate cameras, you must be running at least [integration
v5.12.0](https://github.com/blakeblackshear/frigate-hass-integration/releases/tag/v5.12.0).
 - Closes: #2191 

Includes a significant refactor of cameras, and the introduction of a
`2-way-audio` capability that is dynamically fetched from `go2rtc`. One
gotcha is if you previously had a substream with 2-way audio, you may
need to modify

```yaml
 - camera_entity: camera.foo
    capabilities:
      disable_except:
        - substream
```

... to ...

```yaml
 - camera_entity: camera.foo
    capabilities:
      disable_except:
        - substream
        - 2-way-audio
```

src/camera-manager/manager.ts

@@ -752,12 +752,7 @@ export class CameraManager {
     cameraID: string,
     context?: CameraEndpointsContext,
   ): CameraEndpoints | null {
-    const cameraConfig = this._store.getCameraConfig(cameraID);
-    const engine = this._store.getEngineForCameraID(cameraID);
-    if (!cameraConfig || !engine) {
-      return null;
-    }
-    return engine.getCameraEndpoints(cameraConfig, context);
+    return this._store.getCamera(cameraID)?.getEndpoints(context) ?? null;
   }
 
   public getCameraMetadata(cameraID: string): CameraManagerCameraMetadata | null {