incusd/instance/lxc: Detect bad idmap and find new one #330

Job	Run time
Documentation	5m 17s
System (1.20.x, cluster, dir)	11m 9s
Code	6m 37s
Client (1.20.x, ubuntu-latest)	58s
System (1.20.x, cluster, btrfs)	12m 10s
System (1.20.x, cluster, lvm)	12m 14s
Client (1.20.x, macos-latest)	1m 32s
Client (1.20.x, windows-latest)	2m 54s
System (1.20.x, cluster, zfs)	13m 54s
System (1.20.x, cluster, ceph)	15m 15s
System (1.20.x, cluster, random)	12m 51s
System (1.20.x, standalone, dir)	23m 42s
System (1.20.x, standalone, btrfs)	22m 13s
System (1.20.x, standalone, lvm)	39m 17s
System (1.20.x, standalone, zfs)	42m 45s
System (1.20.x, standalone, ceph)	1h 13m 27s
System (1.20.x, standalone, random)	31m 30s
System (stable, cluster, dir)	10m 42s
System (stable, standalone, dir)	21m 27s
System (tip, cluster, dir)	12m 26s
System (tip, standalone, dir)	22m 22s
	6h 34m 42s

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