[OpenAI] Set up logging for browser (#31239)

### Describe the problem that is addressed by this PR
Fix the failing browser issue in injecting Azure Log Level

sdk/openai/openai/test/public/utils/setup.ts

@@ -0,0 +1,36 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+import type { GlobalSetupContext } from "vitest/node";
+
+enum EnvVarKeys {
+  AZURE_LOG_LEVEL = "AZURE_LOG_LEVEL",
+}
+declare module "vitest" {
+  type MyEnvVarKeys = {
+    [K in keyof typeof EnvVarKeys]: string;
+  };
+  export interface ProvidedContext extends MyEnvVarKeys {}
+}
+
+const defaultLogLevel = "info";
+
+function assertEnvironmentVariable(key: string): string {
+  const value = process.env[key];
+  // handle defaults
+  if (!value) {
+    switch (key) {
+      case EnvVarKeys.AZURE_LOG_LEVEL:
+        return defaultLogLevel;
+      default:
+        throw new Error(`Environment variable ${key} is not defined.`);
+    }
+  }
+  return value;
+}
+
+export default async function ({ provide }: GlobalSetupContext) {
+  for (const key of Object.values(EnvVarKeys)) {
+    provide(key, assertEnvironmentVariable(key));
+  }
+  return function () {};
+}