[User Model] Upgrade to .NET 7

[emawby]

Things I needed to do to get the extension to work

To get extension to recognize dotnet tools
Add .NET Install Tool extension

• .NET SDK not found microsoft/vscode-dotnettools#532 (comment)
• Dotnet workload repair
• Dotnet restore
• Brew remove dotnet
• dotnet workload restore
• Close vscode reopen
• Dotnet workload restore
• Close viscose reopen

To get Android tools to work
Create a new project:

• dotnet new maui
• Dotnet restore
• sudo dotnet workload restore
• dotnet build -t:InstallAndroidDependencies -f:net7.0-android -p:AndroidSdkDirectory="$HOME/Library/Android/sdk" -p:AcceptAndroidSDKLicenses=True

To choose a debug target:

• command p to pull up pallete

• maui

• choose iOS device

• Click brackets at bottom and pin debug target

To choose the csproj to run and debug

Right click solution and close solution
Click open solution

Description

One Line Summary

This PR bumps to .net7 and uses the new VSCode + extension workflow for developing on mac.

Details

All instances of .net6 were bumped to .net7 and we are no longer using the Xamarin Legacy SDK. Isntead we are using Microsoft.NET.Sdk in our project.
Additionally the project has been updated to run is VSCode with the maui extension.

Motivation

The Xamarin Legacy SDK has been causing issues building on iOS and is no longer receiving support for new iOS versions. We are moving to the .Net SDK for a more consistent and stable developer experience

Scope

project build settings.

Manual testing

Tested iOS and Android builds using VSCode + extensions

Affected code checklist

• Notifications
  • Display
  • Open
  • Push Processing
  • Confirm Deliveries
• Outcomes
• Sessions
• In-App Messaging
• REST API requests
• Public API changes

Checklist

Overview

• I have filled out all REQUIRED sections above
• PR does one thing
  • If it is hard to explain how any codes changes are related to each other then it most likely needs to be more than one PR
• Any Public API changes are explained in the PR details and conform to existing APIs

Testing

• I have included test coverage for these changes, or explained why they are not needed
• All automated tests pass, or I explained why that is not possible
• I have personally tested this on my device, or explained why that is not possible

Final pass

• Code is as readable as possible.
  • Simplify with less code, followed by splitting up code into well named functions and variables, followed by adding comments to the code.
• I have reviewed this PR myself, ensuring it meets each checklist item
  • WIP (Work In Progress) is ok, but explain what is still in progress and what you would like feedback on. Start the PR title with "WIP" to indicate this.

[shepherd-l]

LGTM

I was able to run the example app with Visual Studio Code and initialize OneSignal on
Android Emulator: Pixel 4 API 31
iOS Simulator: iPhone 15 iOS 17