fix: improve stability and provide better error messages

Relates to #628

This MR will add stability to the web app by preventing a crash when CBI Stats or Contributor & Commits fail to fetch.

Some of these are regressions from the Redux refactor.

It also adds better-looking error messages for specific components. e.g. the contact table.

• fix: contact table ugly error msg
• fix: contributor and committer chart error crash
• fix: cbi stats error crash