Unify logo name methods

Unified the calls to get a name to put in a logo into a single place.

Switched single line instances of organisations to use name rather than
formatted name.

Removed title from topical event link as the title contained the same as
the link text making it unnecessary.

https://www.pivotaltracker.com/story/show/45936735
Merge pull request #330 from alphagov/logo-formatted-name

Unify logo name methods

https://www.pivotaltracker.com/story/show/45936735