Apply custom dev support headers to iOS WebSocket connections

Summary:
## Summary:

Apply custom HTTP headers from `RCTDevSupportHttpHeaders` to all WebSocket
connections created by `RCTWebSocketModule`. This ensures that auth tokens and
other custom headers configured via the dev support header API are included in
WebSocket upgrade requests.

## Changelog:

[IOS][CHANGED] - Apply custom dev support HTTP headers to WebSocket connections

## Test Plan:

Verified that the `RCTDevSupportHttpHeaders` singleton is called to apply
headers to the mutable URL request before creating the SRWebSocket instance.

## Facebook:
Applied from nest/mobile/apps/atod-sample/patches/react-native+0.83.1+005+atod-websocket-ios.patch

Differential Revision: D95037876

Author: Riccardo Cipolleschi

packages/react-native/React/CoreModules/RCTWebSocketModule.mm

@@ -12,6 +12,7 @@
 #import <FBReactNativeSpec/FBReactNativeSpec.h>
 #import <React/RCTAssert.h>
 #import <React/RCTConvert.h>
+#import <React/RCTDevSupportHttpHeaders.h>
 #import <React/RCTUtils.h>
 #import <SocketRocket/SRWebSocket.h>
 
@@ -114,6 +115,8 @@ - (void)invalidate
     }];
   }
 
+  [[RCTDevSupportHttpHeaders sharedInstance] applyHeadersToRequest:request];
+
   SRWebSocket *webSocket = [[SRWebSocket alloc] initWithURLRequest:request protocols:protocols];
   [webSocket setDelegateDispatchQueue:[self methodQueue]];
   webSocket.delegate = self;