Create reducer for profile page data

[tirhelen]

From slack:

these scores on the PROFILE tab -- # snippets and # exercises -- are now causing conflict with PROGRESS TAB, because they share the same reducer. This is overwriting the reducer on the PROGRESS tab, and messes up the PROGRESS calendar, and even causes crashes.

SOLUTION: create a separate reducer for PROFILE TAB, that queries entire history, and displays the TOTALS of snippets and exercises.