Warn when importing a d.bs file but using runtime stuff from them

[TwitchBronBron]

Sometimes you can accidentally import a .d.bs file instead of a .brs or .bs file. We should help developers detect this.

There are valid use cases for wanting to import a .d.bs file (maybe?). But if there's a .brs file next to it, perhaps we should warn you about using that one instead?

Or, we could just warn when using runtime files from an imported d.bs file because they won't exist at runtime.

Also, we probably shouldn't suggest importing .d.bs files at all?