Support emitting to a part file (`.g.dart`)

[TekExplorer]

I have a generator that emits to the shared .g.dart file, but it doesn't appear to work if the source file has aliased imports.

Of course, i cant add any imports myself due to being a part file, so how do I make use of the pre-existing aliased imports?

I'm defining urls in Reference/refer as normal, but I cant seem to find an option that correctly uses the aliased imports without generating imports ourselves, as part files cant have imports.