IssueTracker

Currently clickable (and all of its delegates) do not override the auto invalidation behavior, so whenever any property changes, this causes focus to invalidate, which is particularly expensive, as well as any other invalidation code paths.

For the CLs to merge focusable node into clickable, and also to migrate selectable and toggleable to use a clickable node directly, this means that although there are notable improvements to first composition, the re-use case in the benchmarks is slower as we are doing more work on update.

Another thing to note here is that currently as implemented, just turning off auto invalidation on the main clickable node won't stop its delegates from being invalidated - _everything_ needs to have this turned off.

Because there are still notable improvements to first composition and there are lots of ongoing refactorings here that would make it more costly to disable auto invalidation and then keep that working through everything else we plan to refactor, we decided to still move forward with these changes with the knowledge that when we flatten the nodes / make further refactorings we should be able to disable auto invalidation again and undo these regressions. This bug is to track that, and also to make sure we fix this regression before next beta.