Repository: flutter
Issue: [Desktop] TextField has too generous selection area
Labels: a: text input,framework,f: material design,a: desktop,P2,team-text-input,triaged-text-input

## Steps to Reproduce

1. Execute `flutter run` on the code sample <!-- (see "Code sample" section below) -->
2. Drag mouse cursor above the decoration label and helper texts

**Expected results:** <!-- what did you want to see? -->

No text selection when dragging outside TextField's border.

**Actual results:** <!-- what did you see? -->

Text selection works outside TextField's visual bounds.

<details>
<summary>Code sample</summary>

<!--
      Please create a minimal reproducible sample that shows the problem
      and attach it below between the lines with the backticks.

      To create it you can use `flutter create bug` command and update the `main.dart` file.

      Alternatively, you can use https://dartpad.dev/
      which is capable of creating and running small Flutter apps.

      Without this we will unlikely be able to progress on the issue, and because of that
      we regretfully will have to close it.
-->

```dart
import 'package:flutter/material.dart';

void main() {
  runApp(
    MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('TextField')),
        body: Padding(
          padding: const EdgeInsets.all(48.0),
          child: TextField(
            controller: TextEditingController(text: 'text field text field'),
            decoration: const InputDecoration(
              border: OutlineInputBorder(),
              labelText: 'label label label label label label label label',
              helperText: 'helper helper helper helper helper helper helper',
            ),
          ),
        ),
      ),
    ),
  );
}
```

</details>

<details>
  <summary>Logs</summary>
<!-- Finally, paste the output of running `flutter doctor -v` here. -->

```
[✓] Flutter (Channel stable, 2.10.2, on Ubuntu Jammy Jellyfish (development branch) 5.15.0-18-generic, locale en_US.UTF-8)
    • Flutter version 2.10.2 at /home/jpnurmi/.fvm/versions/stable
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 097d3313d8 (10 days ago), 2022-02-18 19:33:08 -0600
    • Engine revision a83ed0e5e3
    • Dart version 2.16.1
    • DevTools version 2.9.2

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at /home/jpnurmi/Android/Sdk
    • Platform android-31, build-tools 31.0.0
    • ANDROID_SDK_ROOT = /home/jpnurmi/Android/Sdk
    • Java binary at: /home/jpnurmi/Android/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7249189)
    • All Android licenses accepted.

[✓] Linux toolchain - develop for Linux desktop
    • Ubuntu clang version 13.0.0-9
    • cmake version 3.22.1
    • ninja version 1.10.1
    • pkg-config version 0.29.2

[✓] Android Studio (version 2020.3)
    • Android Studio at /home/jpnurmi/Android/android-studio
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7249189)

[✓] VS Code
    • VS Code at /snap/code/current
    • Flutter extension version 3.34.0

[✓] Connected device (1 available)
    • Linux (desktop) • linux • linux-x64 • Ubuntu Jammy Jellyfish (development branch) 5.15.0-18-generic

[✓] HTTP Host Availability
    • All required HTTP hosts are available

• No issues found!
```
</details>

https://user-images.githubusercontent.com/140617/156029103-bd813661-c834-4524-a3d6-3680081bcd22.mp4