scheduleMicrotask utils removed in favor of dart:async

getQueryData wrong arrangment of arguments
Query & Retryer's future property is replaced with Completer
queryFn, fetchFn & fn types corrected
exported all the functions/class/enum  from core (incomplete)
flutter dependency dropped since the core is a Dart package

packages/fl_query/pubspec.yaml

@@ -5,11 +5,11 @@ homepage: https://github.com/KRTirtho/fl-query
 
 environment:
   sdk: ">=2.15.1 <3.0.0"
-  flutter: ">=1.17.0"
+  # flutter: ">=1.17.0"
 
 dependencies:
-  flutter:
-    sdk: flutter
+  # flutter:
+  #   sdk: flutter
   meta: ^1.3.0
   path: ^1.8.0
   hive: ^2.0.0
@@ -27,4 +27,4 @@ dev_dependencies:
   lints: ^1.0.1
 
 # The following section is specific to Flutter.
-flutter:
+# flutter: