Browser-Refresh Moves the User Back to User-Registration Page about planning-poker

[ingomohr]

@eum2o see #5 for the change.

• ℹ️ Pls note that there might (or might not) be better solutions to this. I'm still new to all this React-hooks-thingie-stuff.
• ℹ️ Pls also note that we could use localStorage instead of (or in addition to) sessionStorage. But I guessed that a new browser session should start with a fresh page. But maybe that isn't what we want when we think about it.
  • If you want, I can change it to use the localStorage instead, for this issue.

Manual Integration Test

• Started server as described on readme (only using port 5001 instead of 5000 b/c already in use)
• Started app w/ npm start
• Verified that app starts on submit-username view
• Entered name and hit ENTER
• Estimation stuff is now displayed
• Invoked CMD+R (i.e. CTRL+R on Windows) to refresh the browser
• Estimation stuff is still displayed with my name ✅