[Sentry MAUI iOS] Add Attachements to native Crash Events on iOS

Creating new Feature request as suggested in [#3545]()

### Problem Statement

Sentry MAUI SDK does not have ability to attach files to native crash events on iOS.

**Package**
Sentry

**.NET Flavor**
.NET

**.NET Version**
8.0.407

**OS**
iOS

**SDK Version**
5.2.0

**Self-Hosted Sentry Version**
NA

**Steps to Reproduce**

1. Create a .NET MAUI iOS app and install Sentry NuGet package;
2. Configure Sentry so that reported events should have attachments:

```
SentrySdk.Init(options =>
{
options.Dsn = "...";
});
SentrySdk.ConfigureScope(scope =>
{
scope.AddAttachment("path/to/existing/file.txt", AttachmentType.Default, MediaTypeNames.Text.Plain);
});
```

1. Generate crashes using SentrySdk.CauseCrash(CrashType.Native)

**Expected Result**
All reported native crash events should have file.txt file added as an attachment.

**Actual Result**
Crash generated with parameter CrashType.Native is reported but contains no attachments.

### Solution Brainstorm

I have also attempted adding attachments to native crash events using the SetBeforeSend callback, but SetBeforeSend is not invoked for native crashes on iOS. This is already reported in [#3549]()

An option could be to invoke a callback (similar to [AppCenter's hasCrashedInLastSession()]()) where attachments and other additional information can be added to crash report before it is sent to Sentry.