Luks Blackbox Testing add tpm validation support.

Feature Request

When testing luks and using a non static clevis binding as developer I would like to know that not only does the device get encrypted; But I want to verify the binding I used is what is reported after ignition runs.

Add support for ClevisBinding verification in the blackbox tests.

As an example,

func LuksWithTPM() types.Test {
	name := "tpm.filesystem.luks.encrypt"
	in := types.GetBaseDisk()
	out := types.GetBaseDisk()
	mntDevices := []types.MntDevice{
		{
			Label:        "OEM",
			Substitution: "$DEVICE",
		},
	}
	config := `{
		"ignition": { "version": "$version" },
		"storage": {
		  "disks": [
			{
			  "device": "$DEVICE",
			  "partitions": [
				{
					"label": "luks-device",
					"sizeMiB": 0,
					"startMiB": 0
				}
				],
				"wipe_table": true
			}
		  ],
		  "luks": [
			{
			  "clevis": {
				"tpm2": true
			  },	
			  "device": "$DEVICE",
			  "name": "$UUID",
			  "wipe_volume": true
			}
		  ]
		}
	}`

Would be verified by

in[0].Partitions.GetPartition("OEM").ClevisBinding = ""
out[0].Partitions.GetPartition("OEM").ClevisBinding = "tpm2"

Start in the Go blackbox tests covering LUKS encryption and read how test input and output partitions are represented. Run the relevant LUKS blackbox tests, then add ClevisBinding verification so the TPM example reports an empty input binding and tpm2 in the output.