bug: Inputs with icons are strange

### Prerequisites

- [X] I have read the [Contributing Guidelines](https://github.com/ionic-team/ionic-framework/blob/main/docs/CONTRIBUTING.md#creating-an-issue).
- [X] I agree to follow the [Code of Conduct](https://ionicframework.com/code-of-conduct).
- [X] I have searched for [existing issues](https://github.com/ionic-team/ionic-framework/issues) that already report this problem, without success.

### Ionic Framework Version

v8.x

### Current Behavior

Hi,

Currently inputs with icons are strange, both the normal inputs and the new "ion-input-password-toggle" tag.

According to https://ionicframework.com/docs/api/input#start-and-end-slots-experimental the icons go inside the input, but they look small and without padding.

1. The input is stuck to the icon and is very small compared to the old way.
2. In ion-input-password-toggle, if you add an icon to the right side, for example indicating that something is wrong, the icon is not the same size as the eye.
3. In a normal input, if you put two icons at the end, apart from being very small, they have no padding.

The last item is the old way in which the icons were outside the input and everything looked fine :(

Greetings to the whole team.

### Expected Behavior

It is expected that everything looks nice and centered, with the correct sizes in all cases. The old way was nice and looked great.

### Steps to Reproduce

You can check everything at the following address:
https://stackblitz.com/edit/angular-6tcmal?file=src%2Fapp%2Fexample.component.html

### Code Reproduction URL

https://stackblitz.com/edit/angular-6tcmal?file=src%2Fapp%2Fexample.component.html

### Ionic Info

```
Ionic:

Ionic CLI : 7.2.0
Ionic Framework : @ionic/angular 8.3.0
@angular-devkit/build-angular : 18.2.4
@angular-devkit/schematics : 18.2.4
@angular/cli : 18.2.4
@ionic/angular-toolkit : 12.1.1

Capacitor:

Capacitor CLI : 6.1.2
@capacitor/android : not installed
@capacitor/core : 6.1.2
@capacitor/ios : not installed

Utility:

cordova-res : not installed globally
native-run : 2.0.1

System:

NodeJS : v20.16.0 (C:\Program Files\nodejs\node.exe)
npm : 10.8.1
OS : Windows 10
```

### Additional Information

_No response_

Start with the linked StackBlitz reproduction and the Ionic input start/end slots documentation. Compare the rendering of regular inputs and ion-input-password-toggle with one or two end icons, then trace the relevant input components and styling. Done means icons are centered, consistently sized, and padded in all described cases.

由索引模型根据 Issue 内容生成。