This bumps the `@types/vscode` and `engines: vscode` on packages that were using very old versions. These old versions used a `vscode.d.ts` that didn't include proper link support. We've also made a number of fixes and improvements to `vscode.d.ts` that are useful to extension authors
Pick up latest eslint to avoid a nasty warning about using an unsupported version of TS
Also updates the eslint script to be more scoped on which files it checks
