Improve select all functional tests for results selection actions

Currently, our helpers and step definitions of the functional test framework don't have support for executing bulk actions on a results set.

The goal here is to look at the default bulk actions and add functional tests for them based, improving the coverage of the test framework helpers and step definitions. 

For example, a simple functional test could be the following:

1. Perform an assets search for pictures
2. Select all the results
3. Apply a default action (like for instance, add to collection)
4. Confirm all the result set was added to the collection