Merged PR 474091: Add Browser Autodetection for Debugging Blazorwasm

- run `npm i vscode-js-debug-browsers` to add 'vscode-js-debug-browsers' package
- if user does not set their "browser" configuration in launch.json, do some auto detection to find a valid browser, favoring chrome
- Add a message to the user to let them know auto detection was used and what was found. Looks like so in bottom right corner of window:
![image.png](https://devdiv.visualstudio.com/0bdbc590-a062-4c3f-b0f6-9383f67865ee/_apis/git/repositories/ed74911c-9619-4c14-bd9d-20ecfd2250be/pullRequests/474091/attachments/image.png)

Related work items: #1824104

Author: lonitra