[net9.0] Revert: Add MauiUIApplicationDelegate remote notification methods

[Redth]

Unfortunately, when these lifecycle events were added in #23452 we didn't consider the implications of having the methods implemented on the appdelegate had with Apple app store submissions. Basically if the app delegate implements these methods, Apple assumes in their static analysis of the submitted apps that you intend to use them, and will warn about requiring the appropriate entitlements to therefore be declared.

Given there's no obvious/easy way to conditionally export these selectors at this time, we are reverting the change to maintain the no warning/no error submission behaviour.

For more information and to track future potential implementations of these lifecycle events, follow: #24237

[rmarinho]

/Users/builder/azdo/_work/1/s/src/Core/src/LifecycleEvents/iOS/iOSLifecycle.cs(21,24): error RS0016: Symbol 'RegisteredForRemoteNotifications' is not part of the declared public API (https://github.com/dotnet/roslyn-analyzers/blob/main/src/PublicApiAnalyzers/PublicApiAnalyzers.Help.md) [/Users/builder/azdo/_work/1/s/src/Core/src/Core.csproj::TargetFramework=net9.0-maccatalyst17.5]
/Users/builder/azdo/_work/1/s/src/Core/src/LifecycleEvents/iOS/iOSLifecycle.cs(22,24): error RS0016: Symbol 'ReceivedRemoteNotification' is not part of the declared public API (https://github.com/dotnet/roslyn-analyzers/blob/main/src/PublicApiAnalyzers/PublicApiAnalyzers.Help.md) [/Users/builder/azdo/_work/1/s/src/Core/src/Core.csproj::TargetFramework=net9.0-maccatalyst17.5]
/Users/builder/azdo/_work/1/s/src/Core/src/LifecycleEvents/iOS/iOSLifecycle.cs(21,24): error RS0016: Symbol 'RegisteredForRemoteNotifications' is not part of the declared public API (https://github.com/dotnet/roslyn-analyzers/blob/main/src/PublicApiAnalyzers/PublicApiAnalyzers.Help.md) [/Users/builder/azdo/_work/1/s/src/Core/src/Core.csproj::TargetFramework=net9.0-ios17.5]
/Users/builder/azdo/_work/1/s/src/Core/src/LifecycleEvents/iOS/iOSLifecycle.cs(22,24): error RS0016: Symbol 'ReceivedRemoteNotification' is not part of the declared public API (https://github.com/dotnet/roslyn-analyzers/blob/main/src/PublicApiAnalyzers/PublicApiAnalyzers.Help.md) [/Users/builder/azdo/_work/1/s/src/Core/src/Core.csproj::TargetFramework=net9.0-ios17.5]
    0 Warning(s)
    4 Error(s)

Also please rebase, we fixed some tests on net9.0

[jfversluis]

@mikeparker104

[PureWeen]

/rebase