Add user agent detail to client config for v2 sample apps

[emmac3]

As of the January SDK release, all of our Square Connect SDKs now support a custom telemetry string userAgentDetail. We want to populate this field and use this new functionality to start capturing usage metrics on each sample app. In order to do that we need to add code in each sample app to set this usage string to the name of that sample app.

• updated square sdk version to v22 for all v2 sample apps
• added userAgentDetail to all v2 sample apps
• ran apps locally to verify that the user agent detail information is included using API logs
• fixed minor issues with README docs and certain styling issues
• v1 and oauth sample apps will be addressed in a separate PR

[azlee]

Can you add the user agent detail to the graphql app as well - https://github.com/square/connect-api-examples/blob/master/connect-examples/v2/graphql-sample-app/bin/script/seed-data.js#L31-L34