Moved morph dependency to new repo (#19618)

```release-note
NONE
```

Co-authored-by: Ibrahim Serdar Acikgoz <serdaracikgoz86@gmail.com>

vendor/github.com/mattermost/morph/models/migration.go

@@ -0,0 +1,58 @@
+package models
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strconv"
+)
+
+type Migration struct {
+	Bytes     io.ReadCloser
+	Name      string
+	RawName   string
+	Version   uint32
+	Direction Direction
+}
+
+func NewMigration(migrationBytes io.ReadCloser, fileName string) (*Migration, error) {
+	m := Regex.FindStringSubmatch(fileName)
+
+	var (
+		versionUint64 uint64
+		direction     Direction
+		identifier    string
+		err           error
+	)
+
+	if len(m) == 5 {
+		versionUint64, err = strconv.ParseUint(m[1], 10, 64)
+		if err != nil {
+			return nil, err
+		}
+		identifier = m[2]
+		direction = Direction(m[3])
+	} else {
+		return nil, fmt.Errorf("could not parse file: %s", fileName)
+	}
+
+	return &Migration{
+		Version:   uint32(versionUint64),
+		Name:      identifier,
+		RawName:   fileName,
+		Bytes:     migrationBytes,
+		Direction: direction,
+	}, nil
+}
+
+func (m *Migration) Query() (string, error) {
+	buf := new(bytes.Buffer)
+	if _, err := buf.ReadFrom(m.Bytes); err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}
+
+func (m *Migration) Close() error {
+	return m.Bytes.Close()
+}

vendor/github.com/mattermost/morph/models/parse.go

@@ -0,0 +1,23 @@
+package models
+
+import (
+	"fmt"
+	"regexp"
+)
+
+// Direction is either up or down.
+type Direction string
+
+const (
+	Down Direction = "down"
+	Up   Direction = "up"
+)
+
+var (
+	ErrParse = fmt.Errorf("no match")
+)
+
+// Regex matches the following pattern:
+//  123_name.up.ext
+//  123_name.down.ext
+var Regex = regexp.MustCompile(`^([0-9]+)_(.*)\.(` + string(Down) + `|` + string(Up) + `)\.(.*)$`)