fix(funnels): Show cohort names when breaking down by cohorts

[macobo]

Problem

Cohort names would not display when breaking down by cohorts in funnels. Instead, a random number would be shown.

Examples from current master:

Changes

Root cause of this was poor typing, which was fixed by:

• calling formatBreakdownLabel with all required arguments and making these arguments mandatory
• undoing wrapping added by getBreakdownStepValues to all breakdown values when rendering a breakdown value

Also fixed some incorrect typing

How did you test this code?

Screenshots:

[Twixes]

Fair enough – can you just add handling for "All Users"?