* refactor: Remove uses of AnyDuringMigration from trashcan.ts.
* refactor: Remove uses of AnyDuringMigration in bubble.ts.
* refactor: Remove uses of AnyDuringMigration from connection_checker.ts.
* refactor: Remove uses of AnyDuringMigration from connection_db.ts.
* refactor: Remove uses of AnyDuringMigration in contextmenu_items.ts.
* refactor: Remove uses of AnyDuringMigration from grid.ts.
* refactor: Remove uses of AnyDuringMigration from i_drag_target.ts.
* refactor: Remove uses of AnyDuringMigration from i_ast_node_location_svg.ts.
* refactor: Remove uses of AnyDuringMigration from i_ast_node_location_with_block.ts.
* refactor: Remove uses of AnyDuringMigration from i_autohideable.ts.
* refactor: Remove uses of AnyDuringMigration from i_block_dragger.ts.
* refactor: Remove uses of AnyDuringMigration from i_bounded_element.ts.
* refactor: Remove uses of AnyDuringMigration from i_bubble.ts.
* refactor: Remove uses of AnyDuringMigration from i_collapsible_toolbox_item.ts.
* refactor: Remove uses of AnyDuringMigration from i_connection_checker.ts.
* refactor: Remove uses of AnyDuringMigration from i_contextmenu.ts.
* refactor: Remove uses of AnyDuringMigration in i_copyable.ts.
* refactor: Remove uses of AnyDuringMigration from i_deleteable.ts.
* refactor: Remove uses of AnyDuringMigration from i_delete_area.ts.
* refactor: Remove uses of AnyDuringMigration in i_flyout.ts.
* refactor: Remove uses of AnyDuringMigration in i_keyboard_accessible.ts.
* refactor: Remove uses of AnyDuringMigration in i_metrics_manager.ts.
* refactor: Remove uses of AnyDuringMigration from i_movable.ts.
* refactor: Remove uses of AnyDuringMigration in i_positionable.ts.
* refactor: Remove uses of AnyDuringMigration in i_selectable_toolbox_item.ts.
* refactor: Remove uses of AnyDuringMigration from i_selectable.ts.
* refactor: Remove uses of AnyDuringMigration in i_serializer.ts.
* refactor: Remove uses of AnyDuringMigration from i_styleable.ts.
* refactor: Remove uses of AnyDuringMigration in i_toolbox.ts.
* refactor: Make non-null checks explicit.