Support removing autodiscovered projects from workspace

[ssm951]

Hello, it seems like this extension auto-discovering projects causes issues when there are folder structures in the node_modules folder (that some dependency has) that contains a template maven or gradle project. Every time on startup, the extension will tell me that building those projects fail.

I noticed that the auto-discovery mechanism doesn't ignore the VS code excluded folders, including the node_modules folder. It would have been fine if there was an ability to exclude them from the workspace. Having a way to right click on a project in the Projects pane, and exclude it from the extension, would fix this for me.

In the meantime, the extension auto-discovery mechanism should also get updated to ignore folders that VS Code is already configured to ignore.