Implementing the move event required to pass the IPC socket to
`i3_ipc_callback_t`, because we won't get notified about any visibility
changes of other workspaces. That's why we query all workspaces again
after a focused workspace was moved.
A renamed workspace caused yambar to abort in a failed assertion,
because workspace lookup was done by name and the `rename` event was not
implemented. To resolve this issue this patch implements the `rename`
event and as a necessity changes workspace_lookup() to use ids instead