Add test-client workflow

On push trigger for now to test it.
Can be trigger manually to test that the mithril-client can list,
download and restore on each supported environment.

.github/workflows/test-client.yml

@@ -0,0 +1,52 @@
+name: Mithril Client multi-platform test
+
+#on: workflow_dispatch
+on: push
+
+jobs:
+  test:
+    strategy:
+      fail-fast: false
+      matrix:
+#        os: [ ubuntu-22.04, macos-12, windows-latest ]
+        os: [ ubuntu-22.04 ]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v3
+        with:
+          path: sources/
+
+      - name: Prepare environment variables
+        id: prepare
+        run: |
+          echo "sha=$(git ls-remote {{ github.repositoryUrl }} refs/heads/main | cut -f 1)" >> $GITHUB_OUTPUT
+          
+          echo "NETWORK=preview" >> $GITHUB_ENV
+          echo "AGGREGATOR_ENDPOINT=https://aggregator.pre-release-preview.api.mithril.network/aggregator" >> $GITHUB_ENV
+          echo "GENESIS_VERIFICATION_KEY=$(wget -q -O - https://raw.githubusercontent.com/input-output-hk/mithril/main/TEST_ONLY_genesis.vkey)" >> $GITHUB_ENV
+          
+      - name: Checkout binary
+        uses: dawidd6/action-download-artifact@v2
+        with:
+          name: mithril-distribution-Linux-X64
+          path: ./
+          commit: ${{ steps.prepare.outputs.sha }}
+          workflow: ci.yml
+          workflow_conclusion: success
+
+      - name: Set permissions
+        run: | 
+          chmod +x ./mithril-client
+          ls -l
+          
+      - name: List and get last snapshot digest
+        run: |
+          ./mithril-client list
+          echo "SNAPSHOT_DIGEST=$(./mithril-client list --json | jq -r ".[0].digest)" >> $GITHUB_ENV
+      
+      - name: Download Latest Snapshot
+        run: ./mithril-client download $SNAPSHOT_DIGEST
+
+      - name: Restore Latest Snashot
+        run: ./mithril-client restore $SNAPSHOT_DIGEST