Now that VSCode ask projects to work within devcontainer, we need VSCode workspace to support opening many projects using devcontainer.

I have 3 projects/components using devcontainer, I can work on each of them in a different VSCode window.

But, it would be way easier to enable working in all three of them in the same window using the "Add folder to workspace", but when doing so, the devcontainer functions are lost.

The feature is to enable us to work with many dev container within the same workspace. Allowing us to open a terminal in a given devcontainer and have the plugin switch when the file open change from one project to the others, maybe even switch terminal as this is done.

i.e. if the open file is folder A, a terminal is presented in the devcontainer of folder A. and all the plugins now act upon folder A (such as CMake Build). If the current file is Folder B, then terminal for devcontainer of folder B is presented, and VSCode plugin switches to folder B devcontainer one.