blockdev: Remove deprecated types and functions

Remove the old partition table types and functions that have been
replaced by the unified Device API:

- Remove SfDiskOutput, Partition, PartitionType, PartitionTable types
- Remove partitions_of() function (use list_dev() + Device methods)
- Remove find_parent_devices() function (use Device::list_parents/root_disk)
- Remove split_lsblk_line() helper (no longer needed without --pairs)
- Remove ESP_ID_MBR constant (MBR ESP support via type codes removed)
- Remove regex dependency (was only used by split_lsblk_line)

The new Device API provides equivalent functionality:
- Device::find_partition_of_type() replaces PartitionTable::find_partition_of_type()
- Device::find_partition_of_esp() replaces PartitionTable::find_partition_of_esp()
- Device::find_device_by_partno() replaces PartitionTable::find_partno()
- Device::root_disk() replaces find_parent_devices() loop pattern

Also adds node() as an alias for path() for compatibility, and updates
tests to verify the new Device methods.

Assisted-by: Claude Code (claude-opus-4-5-20251101)
Signed-off-by: ckyrouac <ckyrouac@redhat.com>

Author: ckyrouac

Cargo.lock

@@ -17,7 +17,6 @@ camino = { workspace = true, features = ["serde1"] }
 cap-std-ext = { workspace = true, features = ["fs_utf8"] }
 fn-error-context = { workspace = true }
 libc = { workspace = true }
-regex = { workspace = true }
 rustix = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }