Add a lint for using global function names

[nex3]

Now that the module system has launched, functions that are available from modules should be called using those modules rather than using their global aliases. The canonical list of which functions have moved to which modules is in the module system proposal.

Maybe the lint should also link to the Sass migrator documentation to help users migrate automatically?

cc @rambleraptor

[kristerkari]

New rule released in v3.16.0:
https://github.com/kristerkari/stylelint-scss/releases/tag/3.16.0