update typescript generation to work in strict mode

[henriiik]

The changes in this PR fixes the issues brought up in #279.

The problem is that in typescripts strict mode, the type {} only matches empty objects ex const someVar = {}, and not anything else.

The following changes are made:

1. update tsconfig.json to use strict
2. update MethodInfo/AbstractClientBase/ClientReadableStream to be generic over Request and Response types
3. update ClientReadableStream.on to have correct callback type depending on type argument
4. update generated clients to allow passing of null as credentials and options

I could not figure out where credentials and options are used so I could not figure out the correct types. If you could point me in the right direction that would be great! :)

[stanley-cheung]

Sorry for the late reply. Thanks very much for the contribution! TypeScript help is sorely needed right now!

credentials and options should both be an object of string: string, but they are both unused right now.

[henriiik]

Thanks for the info @stanley-cheung 🙂

I have updated the PR with the correct types for credentials and options and it should be good to merge now.

[stanley-cheung]

Thanks for your contributions!