Unable to view group page when indexer is unavailable

[ryanchristo]

Related to #131

As a followup to #112, we need to make sure we are handling a scenario when the indexer endpoint is unavailable. In the current implementation, if the indexer endpoint is unavailable, group pages cannot be viewed. We need to ensure that we are handling the errors in such a case and not preventing the use of the application if the indexer is unavailable.