make topic metadata available to functions

[uedun]

Is this a BUG REPORT or FEATURE REQUEST?:
Feature request
What happened:
We have a use case for certain parameters like partitions, offset, keys that are not available in the events object for consumption by functions
What you expected to happen:
Make those parameters available to the functions since they are already present in the controller
How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?:
I have a working fork that we use internally and would be happy to contribute this if it is a desired feature.

Environment:

• Kubernetes version (use kubectl version):
  Client Version: version.Info{Major:"1", Minor:"19", GoVersion:"go1.15.2"
  Server Version: version.Info{Major:"1", Minor:"15+" GoVersion:"go1.12.17"}
• Kubeless version (use kubeless version):
  Kubeless version: v1.0.7-dirty
• Cloud provider or physical cluster:
  AWS eks cluster

[sepetrov]

I also think this is valuable information, especially for cases where a function cannot handle the message for some reason.
How do you suggest making this information available to the handler? What I had in mind is using the request headers, like in here.

[uedun]

I also think this is valuable information, especially for cases where a function cannot handle the message for some reason.
How do you suggest making this information available to the handler? What I had in mind is using the request headers, like in here.

This is exactly what I have done. Here is a PR