Add CLI to interact with Diun through gRPC (#382)

Add simple CLI to interact with Diun through gRPC
Create image and notif proto services
Compile and validate protos through a dedicated Dockerfile and bake target
Implement proto definitions
Move server as `serve` command
New commands `image` and `notif`
Refactor command line usage doc
Better CLI error handling
Tools build constraint to manage tools deps through go modules
Add upgrade notes

Co-authored-by: CrazyMax <crazy-max@users.noreply.github.com>

.github/workflows/build.yml

@@ -25,6 +25,21 @@ env:
   GHCR_SLUG: ghcr.io/crazy-max/diun
 
 jobs:
+  validate:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      -
+        name: Validate
+        uses: docker/bake-action@v1
+        with:
+          targets: validate
+
   test:
     runs-on: ubuntu-latest
     steps:
@@ -49,7 +64,9 @@ jobs:
 
   build:
     runs-on: ubuntu-latest
-    needs: [ test ]
+    needs:
+      - validate
+      - test
     steps:
       -
         name: Checkout

.github/workflows/validate.yml

@@ -1,28 +0,0 @@
-name: validate
-
-on:
-  push:
-    branches:
-      - 'master'
-    tags:
-      - 'v*'
-      - 'dockerfile/*'
-  pull_request:
-    branches:
-      - 'master'
-
-jobs:
-  validate:
-    runs-on: ubuntu-latest
-    steps:
-      -
-        name: Checkout
-        uses: actions/checkout@v2
-      -
-        name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v1
-      -
-        name: Validate
-        uses: docker/bake-action@v1
-        with:
-          targets: validate