Analyser fixes (#10)

Co-authored-by: maksnevor <maksnevor14@gmail.com>

analysis_options.yaml

@@ -2,10 +2,10 @@
 # Lint rules to be used for apps without developer facing API. i.e. command line tools and Flutter applications
 ##
 analyzer:
-  strong-mode:
+  language:
     # Will become the default once non-nullable types land
     # https://github.com/dart-lang/sdk/issues/31410#issuecomment-510683629
-    implicit-casts: true
+    strict-casts: true
   errors:
     # treat missing required parameters as a warning (not a hint)
     missing_required_param: warning
@@ -498,11 +498,6 @@ linter:
     # https://dart-lang.github.io/linter/lints/prefer_double_quotes.html
     # - prefer_double_quotes
 
-    # Prevent confusion with call-side when using named parameters
-    # pedantic: enabled
-    # https://dart-lang.github.io/linter/lints/prefer_equal_for_default_values.html
-    - prefer_equal_for_default_values
-
     # Single line methods + implementation makes it hard to write comments for that line.
     # Dense code isn't necessarily better code.
     # pedantic: disabled