Adds a repository for "saved tools".
English and Welsh translations for saved tools.
Support to check if the user has saved data for a tool using `#has_data_for` on the User class.
List tools that the user has saved data for on the profile page.
Basic acceptance test to test the "saved tools" list.
Frontend tweaks for Saved Tools
Tweaks to the `#saved_tools` helper method and the Warden sign-in feature step as per PR suggestions.
Fix to acceptance test when asserting for the tool title.
Use the more idiomatic `#data_for?` over `#has_data_for`.
Merge pull request #798 from moneyadviceservice/saved_tools

"Saved tools" on the profile page.