mol-state & plugin: wip

src/mol-plugin/behavior.ts

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

src/mol-plugin/command/command.ts

src/mol-plugin/command/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-plugin/ui/plugin.tsx

src/mol-state/action.ts

src/mol-state/action/manager.ts

src/mol-state/state.ts

src/mol-state/state/selection.ts

src/mol-state/tree/builder.ts