build and develop using docker

- add DevContainer
  note that integration tests will not run in devcontainer
- allow to build using docker buildx bake

Signed-off-by: Falk Werner <falk.werner@gmx.net>

docker-bake.hcl

@@ -0,0 +1,10 @@
+group "default" {
+  targets = ["build"]
+}
+
+target "build" {
+    dockerfile = "Dockerfile"
+    context = "."
+    targets = ["build"]
+    output = ["out"]
+}