Cross-file intellisense doesn't work with file provider

[ejizba]

Add two typescript files. One with:

export function helloWorld() {
    console.log('hello world');
}

And one with:

import * as test from './'

Type 'ctrl+space' after the slash to bring up intellisense

Expected:

Actual:

[PrashanthCorp]

I came across this comment thread that suggests this may be unsupported at this time.

[wwlorey]

Adding "azurestorage" to supportedSchemes doesn't fix intellisense on its own. We're waiting for VS Code to allow this sort of functionality (microsoft/vscode#59650)

[ejizba]

VS Code issue was fixed: microsoft/vscode#59650 (comment)

Good enough for us at this point.