Refactor Helm deployments (#341)

* Wrap KMS deployment in one main chart that
deploys all other services. Other services will follow.
* Use .tgz via helm-package as serialization format
* Change Release type to carry chart as byte slice
* Remove KMSConfig
* Use json-schema to validate values
* Extend release.md to mention updating helm charts

cli/internal/helm/loader_test.go

@@ -0,0 +1,34 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package helm
+
+import (
+	"bytes"
+	"encoding/json"
+	"testing"
+
+	"github.com/edgelesssys/constellation/v2/internal/cloud/cloudprovider"
+	"github.com/edgelesssys/constellation/v2/internal/deploy/helm"
+	"github.com/stretchr/testify/assert"
+	"helm.sh/helm/v3/pkg/chart/loader"
+)
+
+func TestLoad(t *testing.T) {
+	assert := assert.New(t)
+
+	chartLoader := ChartLoader{}
+	release, err := chartLoader.Load(cloudprovider.GCP, true, []byte("secret"), []byte("salt"))
+	assert.NoError(err)
+
+	var helmReleases helm.Releases
+	err = json.Unmarshal(release, &helmReleases)
+	assert.NoError(err)
+	reader := bytes.NewReader(helmReleases.ConstellationServices.Chart)
+	chart, err := loader.LoadArchive(reader)
+	assert.NoError(err)
+	assert.NotNil(chart.Dependencies())
+}