Add delete button support to FilterChip

[TahaTesser]

fixes FilterChip should have DeletableChipAttributes/trailing to match Material 3 spec.

Code sample

expand to view the code sample

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return  MaterialApp(
      debugShowCheckedModeBanner: false,
      theme: ThemeData(useMaterial3: true),
      home: const Example(),
    );
  }
}

class Example extends StatelessWidget {
  const Example({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text('FilterChip'),
            const SizedBox(height: 8),
            FilterChip(
              avatar: const Icon(Icons.favorite_rounded),
              label: const Text('FilterChip'),
              selected: true,
              showCheckmark: false,
              onSelected: (bool value) {},
              onDeleted: () {},
              deleteButtonTooltipMessage: 'Delete Me!',
            ),
            const SizedBox(height: 16),
            FilterChip(
              avatar: const Icon(Icons.favorite_rounded),
              label: const Text('FilterChip'),
              onSelected: (bool value) {},
              onDeleted: () {},
            ),
            const SizedBox(height: 48),
            const Text('FilterChip.elevated'),
            const SizedBox(height: 8),
            FilterChip.elevated(
              avatar: const Icon(Icons.favorite_rounded),
              label: const Text('FilterChip'),
              selected: true,
              showCheckmark: false,
              onSelected: (bool value) {},
              onDeleted: () {},
            ),
            const SizedBox(height: 16),
            FilterChip.elevated(
              avatar: const Icon(Icons.favorite_rounded),
              label: const Text('FilterChip'),
              onSelected: (bool value) {},
              onDeleted: () {},
            ),
          ],
        ),
      ),
    );
  }
}

Before

Not possible to add delete button

After

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
• I signed the CLA.
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

[HansMuller]

LGTM