Convert inline comment to block comment, and vice-versa

Issue Type: <b>Feature Request</b> I have several JS lines commented out, like so: ```js // This // is // a // test ``` When I select these lines, there should be a VSC command to convert the inline comments to one block comment. So that the result is: ```js /** * This * is * a * test */ ``` And then the opposite can be allowed, too, so that when I select the block comment, I can run a command to convert them to several inline comments. VS Code version: Code 1.37.1 (f06011ac164ae4dc8e753a3fe7f9549844d15e35, 2019-08-15T16:16:34.800Z) OS version: Darwin x64 18.7.0 <!-- generated by issue reporter -->