post-gen formatter / cleanup

[pkieltyka]

it would be nice to have a post-gen formatter for arbitrary source that cleans generated code like the node server..

as you can see the ugly formatting at https://github.com/webrpc/webrpc/blob/master/_examples/node-ts/server/server.gen.ts

Maybe there is some Go community package out there which can help with general / basic source formatting to help? it doesnt have to be perfect, just it could do stuff like remove the double "\n\n" everywhere, and maybe fix the indentation a bit..

When we generate go code, this isn't an issue because we actually can use goimports like we do so its automatically formatted, but it would be nice to have some basic clean up for arbitrary languages