added displaying of undistributed balance and current month expectations
contains changes from https://review.dev.storj.io/c/storj/storj/+/4867 to be workable
Change-Id: I9cb00d2db5b819a71ceeddf91d6863a6b4fa9034
WHAT: unit tests for vue components and vuex store and environment for it
WHY: to cover frontend part with tests
Change-Id: I2aeaadb200176d4ba0a1406068304785e95d92cd