This commit:
1. Removes the header from the Data Driven Forms wizard
2. Adds padding around the in-page wizard so it is visually consistent
with the images table
3. Refactors the images table header into a re-usable component that is
now used in both the images table and the wizard
4. Allows the repositories table to fill the available vertical space in
the wizard
5. Adjusts the package dual list selectors so that they fill the
available horizontal space in the wizard
