[Improvement] Internal feedback on command-change portal site


There are a few improvement could be made on the [portal site](https://azure-cli-diff-site.azurewebsites.net/) for breaking change tool.
This is the only reason this issue get opened.

From better user experience perspective,

I highlighted several items we may consider to improve within the screenshot.

In addition, I believe that there are many operations running under the hood. By saying that, I personally would not call it a performance issue. (well, if you really want to optimize in future, we may still have room for it...)

But we need to remind users with something like this,
> You may expect this to take xx~yy mins to fetch all results. Please grab a coffee and come back with us.

Let me know anything if you have better suggestion. Thx a lot!