[Bug] [iOS] Semantics reads out from whole control and makes stepper non-interact-able

### Description

Semantic description and hint get read aloud from the Stepper control on iOS by focusing on the whole control. Unfortunately, this means that the - and + buttons cannot be reached.

We should consider propagating these semantic properties down to the individual buttons.

### Steps to Reproduce

1. Run .NET MAUI sln on iOS
2. Navigate to semantics page
3. Turn on VoiceOver
4. Navigate to Stepper

### Expected Behavior

Semantic description and hint should be read aloud from the stepper in a way that the stepper can stil l be interacted with / the buttons are reachable

### Actual Behavior

Setting semantics make screen reader unusable

### Basic Information

- Version with issue:
- Last known good version:
- IDE:
- Platform Target Frameworks:
- iOS:
- Android:
- UWP:
- Android Support Library Version:
- Nuget Packages:
- Affected Devices:

Start by running the .NET MAUI solution on iOS, opening the semantics page, and enabling VoiceOver to reproduce the Stepper behavior. Trace the Stepper semantics handling and verify that the description and hint are announced while the minus and plus buttons remain reachable and interactive.

Written by the indexing model from the issue text.