feat: Add the check-pr script

src/flutter/check-pr.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+# Run before merging a PR. Checks if the formatting is correct.
+# Check if there are any formatting issues
+echo "Checking formatting..."
+dart_format_result=$(dart format --output none --set-exit-if-changed .)
+if [[ ! "$?" = "0" ]]; then
+    echo "Error: dart format indicates that format the code is not formatted properly"
+    echo
+    echo "dart format output:"
+    echo "$dart_format_result"
+    exit 1
+fi
+
+# Check if the linter has any issues
+echo "Checking linter..."
+flutter_analyze_result=$(flutter analyze)
+if [[ ! "$?" = "0" ]]; then
+    echo "Error: flutter analyze indicates that there are lint issues"
+    echo
+    echo "flutter analyze output:"
+    echo "${flutter_analyze_result}"
+    exit 1
+fi
+
+echo "PR looks good!"