This commit collects UI components into a new
'horizon.framework.widgets' module. It also standardizes
the naming pattern for .scss files and makes them hierarchical.
This is one step in a larger effort to restructure the Angular
source. See https://review.openstack.org/#/c/176152/ for the
full set of planned changes.
Change-Id: I2edabd6c43f811a4bb2e3abe982dbc24958ddf93
Partial-Bug: #1454880
5762d0deee