Update SSO Canvas sample

[iMicknl]

Can only be merged after https://learn.microsoft.com/en-us/power-virtual-agents/configure-sso is updated to reflect the new sample.

Microsoft employees can test the new sample via https://blue-beach-0319d6403.2.azurestaticapps.net.

Changes:

• Dependencies: MSAL updated from 1.2.0 to 2.32.0 (latest supported version)
• Fix: Chat canvas will be reloaded after login
• Fix: Interface will reflect if user is logged in
• Enhancement: Add log out button
• Enhancement: Improved user interface

TODO:

• Verify by the product group

• See if we can implement real SSO via MSAL.js, or at least add an example.

• Documentation changes:

  • Change required appliaction type in AAD from WebApp to SPA
  • Reflect recent changes to PVA UI, mobile app now has a token URL not just an ID
  • Add a note on what is actually required to implement SSO, this sample is just for demonstration purposes
  • Do you still need 2 app registrations, it works with one as well? (is this a best practice?).
  • Update small code snippets (and include the script tags for MSAL).

https://learn.microsoft.com/en-us/power-virtual-agents/configure-sso
https://learn.microsoft.com/en-us/power-virtual-agents/preview/configure-web-sso

[HenryJammes]

Adding @Kaiqb as reviewer of this PR.

[alivascu]

Just a note for everyone.

In REAL life scenarios, the PVA chat window should NOT be displayed before you authenticate inside the "parent" website.

Once you log in against the "parent" website, then you can display the PVA chat window, as you will get authenticated automatically inside Web Chat client.

That's the SSO mechanism in the end, you have to log in first in some place, then you can get authenticated automatically in some other places.