refactor: organize plugin to support multiple services (#1)

Co-authored-by: Michael Li <michael.li@hashicorp.com>

.github/workflows/test.yml

@@ -0,0 +1,18 @@
+name: test
+
+on:
+  - workflow_dispatch
+  - push
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+      - name: Set up Go
+        uses: actions/setup-go@6edd4406fa81c3da01a34fa6f6343087c207a568 # v3.5.0
+        with:
+          go-version-file: 'go.mod'
+          cache: true
+      - name: Run Tests
+        run: go test -v ./plugin/...