When the file msedgewebview2.exe is missing, the GetAvailableBrowserVersionString method should return null

When WebView2 on the user's machine is being installed/upgraded, files may be lost, and there are also some other reasons, such as insufficient permissions.
And msedgewebview2.exe is a necessary file for WebView2, and there are some other necessary files.

The current situation is that I manually delete msedgewebview2.exe and use the GetAvailableBrowserVersionString method to return the version number of WebView2 normally, but an error occurs during initialization: the system cannot find the specified file.
In my opinion, the GetAvailableBrowserVersionString method should be added to check whether the file exists. If the file is missing, it should return null, as WebView2 needs to be reinstalled.

reference documents:

Approach 2: Run GetAvailableCoreWebView2BrowserVersionString and evaluate whether the versionInfo is nullptr. nullptr indicates that the WebView2 Runtime isn't installed. This API returns version information for the WebView2 Runtime or for any installed preview channels of Microsoft Edge (Beta, Dev, or Canary).

AB#43299681