Improve the usage and consistency of quotation marks for variable substitutions

I would like to see more variable substitutions available I can use when defining my executed commands. Below are some examples I got from [here](https://code.visualstudio.com/docs/editor/tasks#_variable-substitution):

> ${workspaceRoot} the path of the folder opened in VS Code
> ${workspaceRootFolderName} the name of the folder opened in VS Code without any slashes (/)
> ${fileBasename} the current opened file's basename
> ${fileBasenameNoExtension} the current opened file's basename without the extension
> ${fileDirname} the current opened file's dirname
> ${fileExtname} the current opened file's extension

Thanks!