Conventional Items/Props not recognized with custom Sdk
Description
When using the Uno Sdk users are reporting seeing the squiggle on common items and properties that would not be defined by Uno but are part of the larger project ecosystem such as the ProjectReference or PackageReference
Additionally platform specific properties such as those shown here for Android are not being recognized
Does the custom SDK transitively import the props/targets from the Microsoft.NET.Sdk SDK?
So first the Uno.Sdk determines whether we need the regular Microsoft.NET.Sdk or the Microsfot.NET.Sdk.Web https://github.com/unoplatform/uno/blob/3295c5259e78aed6a47d7a6fb425a52b7ec8d262/src/Uno.Sdk/Sdk/Sdk.props#L14-L18
Then we import the Sdk.props... https://github.com/unoplatform/uno/blob/3295c5259e78aed6a47d7a6fb425a52b7ec8d262/src/Uno.Sdk/Sdk/Sdk.props#L54
For the Sdk.targets we do much more initialization and then load the Microsoft Sdk just before the After.targets https://github.com/unoplatform/uno/blob/3295c5259e78aed6a47d7a6fb425a52b7ec8d262/src/Uno.Sdk/Sdk/Sdk.targets#L25-L29