Moved morph dependency to new repo (#19618)

```release-note
NONE
```

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

vendor/github.com/mattermost/morph/go.mod

@@ -0,0 +1,14 @@
+module github.com/mattermost/morph
+
+go 1.16
+
+require (
+	github.com/dave/jennifer v1.4.1
+	github.com/fatih/color v1.10.0
+	github.com/go-sql-driver/mysql v1.6.0
+	github.com/lib/pq v1.10.0
+	github.com/pkg/errors v0.9.1
+	github.com/spf13/cobra v1.1.3
+	github.com/stretchr/testify v1.3.0
+	modernc.org/sqlite v1.14.3
+)