Voting dApp Improvements

[dragosgd]

Description
While reviewing the Voting dApp tutorial, I discovered 3 potential improvements in the React frontend.

1. No "another prompt is already open" error

• on first try of clicking the "create election" button it opened the wallet, suggested a contract initialization
• switched tab, wallet disappeared as a background window
• now the button does not work anymore since the wallet is open, but there is no error notifying the user of that
• as a potential fix, you can display the error "Another prompt already open"
• E.g on this front-end(sctools) if you don't approve the transaction in the wallet but click back to the browser webpage (so that your Concordium wallet windows is now at the background). And you try to initiate a transaction again by clicking a button, you get the above error.

2. Manually navigating to /create endpoint prompts 404 Not Found from nginx

• if the user goes to that page via the setupElectionPage it will work, but not if he manually inputs the URL
  

3. Change the name in browser tab to something suggestive, not "React app"
   

Steps to Reproduce
Already explained in the Description

Versions

• Software Version: 1.1.3(latest deployed version)
• OS: MacOS
• Browser: Brave(chromium based)