mol-plugin & state: fixes

src/mol-plugin/behavior/built-in/state.ts

src/mol-plugin/context.ts

src/mol-plugin/state/actions/basic.ts

src/mol-plugin/state/transforms/model.ts

src/mol-plugin/ui/controls.tsx

src/mol-state/action/manager.ts

src/mol-state/transformer.ts

src/mol-state/tree/transient.ts