Remove fast-components-msft package and move to @microsoft/fluentui

[chrisdholt]

This issue exists to track the removal of fast-components-msft from the FAST repo in coordination with microsoft/fluentui#14071.

For over a year now, we've been syncing regularly with several of the folks involved with the FluentUI effort in an effort to continually find opportunities to align and converge. We're also an active part of the W3C Open UI effort. While we've always had a desire to converge from a code standpoint, previous requirements and deltas in implementation made it difficult to do so with our now deprecated/archived React implementation. As we've made the shift to focus solely on web components, we believe now is a great time to partner on the FluentUI effort and provide a Web Component offering built on FAST.

The package will move over to the Fluent UI repo without any changes. Initially, we'll continue to publish under the existing namespace until we can land a new package name for the Fluent namespace. You can read more about our long term goals and the details of the move at the issue linked above.