Support Deno `--location` runtime flag

[joshgillies]

This flag controls the Deno runtime enabling it to provide globals like location.href. (Deno docs: https://docs.deno.com/runtime/manual/runtime/location_api).

For my specific use case I'm working on a module which wraps worker-tools/deno-fetch-event-adapter. In order to test this module thoroughly the ability to pass the --location flag would be greatly appreciated.

[lpil]

He has already made a PR @abs0luty !