Feature [#39518117] Re-add company switcher

Added the feature back to the app, but just like the year filter, it
needs to be DRY'd up before the merge happens.
Feature [#39518117] Re-add company switcher

Moved company switcher to general layout template to avoid duplication.
Feature [#39518117] Re-add company switcher

Removes unneeded modification to company decorator.
Merge pull request #91 from rescuedcode/add_company_switcher

Add company switcher