Contribution graph to include discussion comments activity

Description

Currently the contribution graph only represents a summary of issues, merge requests, and push events. "Notes" not included.

Proposal

Have the contribution graph on a persons profile to also represent discussion contribution (comments/new issues etc) .. possibly with a toggle? (in the spirit of conversational development).

I already thought they were part of the graph, but apparently they are not.. imo lets get this in as well.

Implementation:

Comments will count in the graph and will be counted per resource. This would mean that if you make 5 comments in 3 different issues/mr/diffs/commits it would count them as 3 contributions ;)

The line below the graph will state:

In the tooltip, contributions will just be summed up as they are now.

Links / references

cc: @lbennett @stanhu @bkc @tauriedavis @JobV @jschatz1 @awhildy