Albert Callarisa

The git history of this PR seems odd, lots of those commits are unrelated. Do you mind cleaning it up so it only contains commits related to this change?

@elena-kolevska I found [this PR](https://github.com/microsoft/durabletask-python/pull/36) about the downgrade for `grpc_tools`. Do you think that's still relevant? I don't fully understand the problem, the new versions enforce the generated files are...

@sicoyle I couldn't reproduce this. I created a workflow with an activity that runs `sleep(20)` and during the sleep I kill the process. When I run the process again, it...

Thank you for opening the issue! I checked the Go and Java SDKs and they both support custom user objects, using JSON. But both Go and Java have an 'easy'...