feat(http): add HTTP2 support; (#7150)

index.d.ts

@@ -369,6 +369,10 @@ export interface AxiosRequestConfig<D = any> {
   withXSRFToken?: boolean | ((config: InternalAxiosRequestConfig) => boolean | undefined);
   parseReviver?: (this: any, key: string, value: any) => any;
   fetchOptions?: Omit<RequestInit, 'body' | 'headers' | 'method' | 'signal'> | Record<string, any>;
+  httpVersion?: 1 | 2;
+  http2Options?: Record<string, any> & {
+    sessionTimeout?: number;
+  };
 }
 
 // Alias