Initialize table action buttons for lazy-loaded tabs

Various checkbox elements listeners that were set only for
horizon.tables should also be set for tabs which are lazy-loaded
(namely, are defined with `preload = False`) - so, they were moved to
a separate function and reused.  Provide tests for the fixed js
regression using SeleniumTestCase with authorization backend being
stubbed out. This allows to use lazy tabs defined in django code
instead of writing html fixtures (as done for QUnit tests).

Change-Id: I39954ddb439f97238511f6eee5f992213690846f
Closes-Bug: #1191006
Merge "Initialize table action buttons for lazy-loaded tabs"