Add support for new vscode customLabels

[daniheras]

VSCode recently added support for add patterns in order to display custom labels for the vscode tabs: https://code.visualstudio.com/docs/getstarted/userinterface#_customize-tab-labels

I think we can take advantage of this new feature and use it to prefix (for example) monorepo app|package|util related to the open file within the tab.