Add vscode dev container configuration

This enables us to run vscode inside a container[1]
Running it inside a container allows the db and softhsm tests to run
Debugging tests (with breakpoints) in vscode should also be possible when running it inside a container!

[1] https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers

.devcontainer/devcontainer.json

@@ -0,0 +1,26 @@
+// NOTE: YOU MUST RUN docker compose build app && docker compose build BEFORE ATTEMPTING TO RUN DEV CONTAINERS
+
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the
+// README at: https://github.com/devcontainers/templates/tree/main/src/docker-existing-dockerfile
+{
+	"name": "Root Dockerfile"
+	,"dockerComposeFile": "docker-compose.yml"
+	,"service": "app-hsm"
+	,"containerUser": "app"
+	// ,"workspaceMount": "source=${localWorkspaceFolder},target=/workspace,type=bind"
+	,"workspaceFolder": "/workspace"
+
+	// Features to add to the dev container. More info: https://containers.dev/features.
+	,"features": {
+		"ghcr.io/devcontainers/features/go:1": {
+			"version": "1.22",
+			"golangciLintVersion": "1.59.1"
+		},
+		"ghcr.io/devcontainers/features/git:1": {}
+	}
+	// Ensure the container is alive and running
+	,"overrideCommand": true
+
+	// Uncomment to connect as an existing user other than the container default. More info: https://aka.ms/dev-containers-non-root.
+	,"remoteUser": "root"
+}

.devcontainer/docker-compose.yml

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+volumes:
+  apptmpdir:
+  hsmtmpdir:
+services:
+  db:
+    extends:
+      service: db
+      file: ../docker-compose.yml
+  app:
+    extends:
+      service: app
+      file: ../docker-compose.yml
+    volumes:
+      - apptmpdir:/tmp/
+      - ../:/workspace
+  app-hsm:
+    extends:
+      service: app-hsm
+      file: ../docker-compose.yml
+    volumes:
+      - hsmtmpdir:/tmp/
+      - ../:/workspace
+  # We don't really need these for dev work
+  #  but will keep these commented out just in case
+  # monitor:
+  #   extends:
+  #     service: monitor
+  #     file: ../docker-compose.yml
+  # monitor-lambda-emulator:
+  #   extends:
+  #     service: monitor-lambda-emulator
+  #     file: ../docker-compose.yml
+  # monitor-hsm-lambda-emulator:
+  #   extends:
+  #     service: monitor-hsm-lambda-emulator
+  #     file: ../docker-compose.yml
+  # unit-test:
+  #   extends:
+  #     service: unit-test
+  #     file: ../docker-compose.yml