Log rescued exceptions to Sentry

Support noticed that a number of exceptions, such as "Encoding::CompatibilityError (incompatible character encodings: UTF-8 and ASCII-8BIT)", failed to report to Sentry. The rescue_from in the ApplicationController prevented these exceptions from being recorded. This change ensures that these exceptions are properly captured.

Note that Sentry excludes certain exceptions, such as ActiveRecord::RecordNotFound: https://github.com/getsentry/raven-ruby/blob/master/lib/raven/configuration.rb#L152-L161