Disables Token Selection buttons when the server has no Individual Views

[emmebi]

Fixes #656

Description of the Change

This PR disables the 4 Token Selection buttons when a client connects to a server without the Individual View policy.

The change is implemented via an additional method in the ToolbarPanel which can enable and disable the four buttons as a whole.

The method is called when a client connects to a server, if that is needed, and when the client either disconnects as a choice of the user or the server closes the connection.

Tests done

• test with Individual Views: connect to a server with Individual Views enabled, and verify that the 4 buttons remain enabled
• test without Individual Views: connect to a server with Individual Views disabled, and verify that the 4 buttons are disabled
  • verify that if the client disconnects, the buttons are re-enabled
  • verify that if the server disconnects, the buttons are enabled

Possible Drawbacks

None.

Documentation Notes

Buttons before connecting:

Buttons after connecting:

Release Notes

• disables Token Selection buttons when the server has no Individual Views

---

This change is