updated project linter-rules and enforced them

analysis_options.yaml

@@ -24,6 +24,10 @@ linter:
   rules:
     # avoid_print: false  # Uncomment to disable the `avoid_print` rule
     # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
+    file_names: false
+    prefer_relative_imports: true
+    unnecessary_lambdas: true
+    prefer_single_quotes: true
 
 # Additional information about this file can be found at
 # https://dart.dev/guides/language/analysis-options