[feature]: More information when a channel is inactive via RPC

[ziggie1984]

Sometimes channels can become inactive not because the peer is offline but for example when both sides cannot agree on the current state because some updates are not accepted by both sides. So it would be very useful to show this information to the user so that he can potentially react and change his setup.

Request came up during the review of #9182

[Lokeshranjan8]

Hi,I have tested locally by simulating a disconnect and confirmed the inactive channel state. I would like to start working on this PR to extend the RPC response with more detailed inactive reasons.

[ziggie1984]

Be aware that this is not a beginner issue.