Record diagnostics in binlog extraction test

csharp/ql/integration-tests/all-platforms/binlog/diagnostics.expected

@@ -0,0 +1,28 @@
+{
+  "markdownMessage": "C# analysis with build-mode 'none' completed.",
+  "severity": "unknown",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/buildless/complete",
+    "name": "C# analysis with build-mode 'none' completed"
+  },
+  "visibility": {
+    "cliSummaryTable": true,
+    "statusPage": false,
+    "telemetry": true
+  }
+}
+{
+  "markdownMessage": "C# was extracted with build-mode set to 'none'. This means that all C# source in the working directory will be scanned, with build tools, such as Nuget and Dotnet CLIs, only contributing information about external dependencies.",
+  "severity": "note",
+  "source": {
+    "extractorName": "csharp",
+    "id": "csharp/autobuilder/buildless/mode-active",
+    "name": "C# was extracted with build-mode set to 'none'"
+  },
+  "visibility": {
+    "cliSummaryTable": true,
+    "statusPage": true,
+    "telemetry": true
+  }
+}

csharp/ql/integration-tests/all-platforms/binlog/test.py

@@ -1,5 +1,7 @@
 import subprocess
 from create_database_utils import *
+from diagnostics_test_utils import *
 
 subprocess.check_call(["dotnet", "build", "test.sln", "/bl:test.binlog"])
 run_codeql_database_create([], lang="csharp", extra_args=["--build-mode=none", "-Obinlog=test.binlog"])
+check_diagnostics()