split: replace internal packages with images library

Remove all the internal package that are now in the
github.com/osbuild/images package and vendor it.

A new function in internal/blueprint/ converts from an osbuild-composer
blueprint to an images blueprint.  This is necessary for keeping the
blueprint implementation in both packages.  In the future, the images
package will change the blueprint (and most likely rename it) and it
will only be part of the osbuild-composer internals and interface.  The
Convert() function will be responsible for converting the blueprint into
the new configuration object.

vendor/github.com/osbuild/images/pkg/disk/luks.go

@@ -0,0 +1,100 @@
+package disk
+
+import (
+	"fmt"
+	"math/rand"
+
+	"github.com/google/uuid"
+)
+
+type Argon2id struct {
+	Iterations  uint
+	Memory      uint
+	Parallelism uint
+}
+
+type ClevisBind struct {
+	Pin              string
+	Policy           string
+	RemovePassphrase bool
+}
+type LUKSContainer struct {
+	Passphrase string
+	UUID       string
+	Cipher     string
+	Label      string
+	Subsystem  string
+	SectorSize uint64
+
+	// password-based key derivation function
+	PBKDF Argon2id
+
+	Clevis *ClevisBind
+
+	Payload Entity
+}
+
+func (lc *LUKSContainer) IsContainer() bool {
+	return true
+}
+
+func (lc *LUKSContainer) GetItemCount() uint {
+	if lc.Payload == nil {
+		return 0
+	}
+	return 1
+}
+
+func (lc *LUKSContainer) GetChild(n uint) Entity {
+	if n != 0 {
+		panic(fmt.Sprintf("invalid child index for LUKSContainer: %d != 0", n))
+	}
+	return lc.Payload
+}
+
+func (lc *LUKSContainer) Clone() Entity {
+	if lc == nil {
+		return nil
+	}
+	clc := &LUKSContainer{
+		Passphrase: lc.Passphrase,
+		UUID:       lc.UUID,
+		Cipher:     lc.Cipher,
+		Label:      lc.Label,
+		Subsystem:  lc.Subsystem,
+		SectorSize: lc.SectorSize,
+		PBKDF: Argon2id{
+			Iterations:  lc.PBKDF.Iterations,
+			Memory:      lc.PBKDF.Memory,
+			Parallelism: lc.PBKDF.Parallelism,
+		},
+		Payload: lc.Payload.Clone(),
+	}
+	if lc.Clevis != nil {
+		clc.Clevis = &ClevisBind{
+			Pin:              lc.Clevis.Pin,
+			Policy:           lc.Clevis.Policy,
+			RemovePassphrase: lc.Clevis.RemovePassphrase,
+		}
+	}
+	return clc
+}
+
+func (lc *LUKSContainer) GenUUID(rng *rand.Rand) {
+	if lc == nil {
+		return
+	}
+
+	if lc.UUID == "" {
+		lc.UUID = uuid.Must(newRandomUUIDFromReader(rng)).String()
+	}
+}
+
+func (lc *LUKSContainer) MetadataSize() uint64 {
+	if lc == nil {
+		return 0
+	}
+
+	// 16 MiB is the default size for the LUKS2 header
+	return 16 * 1024 * 1024
+}