* Run make ensure on devcontainer creation
Added an ensure target to the dotnet makefile to run `dotnet restore`.
* Add dotnet test explorer and set default vscode settings for it
* Ensure PULUMI_LOCAL_NUGET exists
* Add missing mkdirs
Something has changed in the base image such that the directory
/etc/sudoers.d doesn't exist. Simple fix, `mkdir -p` that directory
before we write to it.
* Installed the go, dotnet, and python extensions by default.
* Set the gopls settings to ignore copies of modules in build directories.
* Set XDG_CACHE_DIR/CONFIG_DIR so that vscode can install go tools.
* Use "containerEnv" instead of "runArgs" to set the container environment.
* Turn on gopls "experimentalWorkspaceModule" so we can open at the root pulumi directory.
* Use "postCreateCommand" to restore all dotnet projects so ominisharp doesn't complain about missing types on startup.
