A temp component to contains unport parts from v7

[wherewhere]

Problem Statement

It has been 3 years since v8 released. But there are still a lot of things which not port from v7. Some of them are only waiting for some never working plans, such as StorageFileHelper and ApplicationDataStorageHelper (CommunityToolkit/Windows#17) are waiting for #229. Some of them are replaced with new components but which has a lot of bugs or missing features which the old one has, such as DataGrid and MarkdownTextBlock. This makes us have to reference v7 which will reference a lot of duplicate things. However, since C#/WinRT, we cannot use v7 in UWP anymore because v7 does not support C#/WinRT. So, we have to use v8 and copy a lot of sources from v7 to make it working like before.

Proposed Solution

We can have a temp component in lab to contains unport parts from v7. Such as CommunityToolkit.WinUI.V7.UI for Microsoft.Toolkit.Uwp.UI. Every time the new one has be released, the parts of it can be removed.

[Shomnipotence]

Agree