Support keeping a bottom sheet with a DraggableScrollableSheet from closing on drag/fling to min extent (#127339)

We were failing to dispose of animation controllers created by `animateTo` when `didUpdateWidget` happens and we null out the `_attachedController`. This would cause the listener added here to fail on a null assertion:

https://github.com/flutter/flutter/blob/fef41cfce0e3582907f6846cf2385470bb17ecd1/packages/flutter/lib/src/widgets/draggable_scrollable_sheet.dart#L135

Without the code change, the test ends up throwing exceptions related to that line. I don't have a great way to verify what this does visually though, hoping for help on that from internal customer.

b/279930163

See cl/527868355 as well.

Fixes https://github.com/flutter/flutter/issues/125709

DraggableScrollableSheet & NestedScrollView  should respect NeverScrollableScrollPhysics

* lerp documentation

* Remove Note, Note That from repo

* Improve BorderSide documentation.

* apply review comments

* Remove superfluous words from comments.

* Revert `win32_window.h`

Which seems to come from `gallery`

* dart fix --apply

* manual fixes

This reverts commit c956121a.

This reverts commit 999356b7.

* Remove single-view assumption from ScrollPhysics

* fix scrollable_dispose_test.dart

* add deprecated method back

* Add a snapAnimationDuration param in DraggableScrollableSheet

* snapAnimationDuration.inMilliseconds > 0

* Update draggable_scrollable_sheet.dart

* copied over changes from

* copied over changes from