Show change server button during connection for free users

[vjmurenko]

✨ Motivation / Context

Currently, on Windows, free users may experience connection hangs when a randomly selected server is unavailable or slow to respond. Unlike Android, there is no way to manually change the server until the connection is fully established, which may never happen in such cases.

On Android, however, the "Change Server" button becomes available after 6 seconds during the connection attempt, allowing the user to select a different server and successfully connect.

This PR brings the same UX improvement to the Windows client by enabling the button after 6 seconds during connection.

Note: I was unable to test the changes due to project complexity and missing dependencies. Please consider this as a suggestion for improvement — the implementation is based on analysis of the current codebase and Android behavior.

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🛠️ Summary of Changes

Align Windows client behavior with Android by showing the "Change Server" button during the connection process for free-tier users.

Previously, the button only appeared after the connection was successfully established. Now it appears during connection if it takes longer than 6 seconds, matching the Android implementation.

🔧 Code Changes:

• Added HasTroubleConnecting() method to IChangeServerModerator interface
• Implemented connection state tracking in ChangeServerModerator
• Updated CanChangeServer logic to allow server changes during connection
• Added HasTroubleConnecting property to ChangeServerComponentViewModel

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📈 Expected Result

This improves the user experience for free-tier users experiencing slow or stuck connections by allowing them to change servers without waiting indefinitely for full connection establishment.