reduce default page size for GET /evaluation/{evalId}/submission/bundle/all

The data warehouse shows that the service:

is very expensive. The following users make many calls, using a page size of 100:

Thomas Yu
smc_statistics
leepc12
prostate_cancer_challenge_admin
DARPA
MMChallenge
BrianMBot
uobcctest
MMChallenge

In addition to investigating why the service call is expensive, we'd like to reduce the default client page size, from 100 to 20.