Remove remaining references to IDPE-me in Cloud2 UI

This is a ticket for discussing potential removal of any remaining references to IDPE `/me` in the Cloud2 portion of the UI. In #5769 we've transitioned away from using idpe `/me` at login and for maintaining the user session in cloud. @gunnaraasen is writing up a ticket for removing its use at logout in cloud.

But idpe `/me` is still called through the `getIDPEMeThunk()` in the `Authenticate` component for two properties, which are used throughout the UI - user name and id. Since those properties can be retrieved from quartz, it's likely possible to remove any calls to idpe /me entirely, and have that data be provided by quartz.