New designs call for a streamlined New Portfolio page, with far
fewer input options. This commit refactors that page according to those
designs.
Some of the route functions in this commit refer to a "step 1" of creating
a new Portfolio. Though there is no "step 2" right now, the designs call
for a multistep flow for Portfolio creation process, so this commit sets
the stage for that.
a097a0ce61