refactor: move custom button to shared dir.

lib/ui/widgets/installerView/custom_material_button.dart

@@ -1,49 +0,0 @@
-import 'package:flutter/material.dart';
-
-class CustomMaterialButton extends StatelessWidget {
-  final Widget label;
-  final bool isFilled;
-  final bool isExpanded;
-  final Function()? onPressed;
-
-  const CustomMaterialButton({
-    Key? key,
-    required this.label,
-    this.isFilled = true,
-    this.isExpanded = false,
-    required this.onPressed,
-  }) : super(key: key);
-
-  @override
-  Widget build(BuildContext context) {
-    return TextButton(
-      style: ButtonStyle(
-        padding: MaterialStateProperty.all(
-          isExpanded
-              ? const EdgeInsets.symmetric(horizontal: 24, vertical: 12)
-              : const EdgeInsets.symmetric(horizontal: 20, vertical: 12),
-        ),
-        shape: MaterialStateProperty.all(
-          StadiumBorder(
-            side: isFilled
-                ? BorderSide.none
-                : BorderSide(
-                    width: 1,
-                    color: Theme.of(context).colorScheme.primary,
-                  ),
-          ),
-        ),
-        backgroundColor: MaterialStateProperty.all(
-          isFilled ? Theme.of(context).colorScheme.primary : Colors.transparent,
-        ),
-        foregroundColor: MaterialStateProperty.all(
-          isFilled
-              ? Theme.of(context).colorScheme.surface
-              : Theme.of(context).colorScheme.primary,
-        ),
-      ),
-      onPressed: onPressed,
-      child: label,
-    );
-  }
-}