Refactored Toolbar

[rachael-phillips]

The related core issue is patternfly/patternfly#1528

[mattnolting]

I spoke to @mcarrano and @mceledonia about toolbar details. Here are the takeaways.

• Elements need to be moved in the DOM, based on content.
  Example 1: when multiple filters are present, these filters need to be moved to the expandable-content element and controlled via filter button toggle.

Example 2: primary and secondary action buttons should move to the actions menu dropdown at specific breakpoint (this may be controlled by JS as well, we'll have to test and work w/design).

• Toolbar may include bulk-select, filter/multiple filters, overflow menu action button w/primary and secondary buttons, chip-group + chips and pagination.