* refactor: move properties to constructor in block_drag_surface.js
* refactor: move properties to constructor in block_svg.js
* refactor: move properties to constructor in block.js
* refactor: move properties to constructor in bubble.js
* refactor: move properties to constructor in connection.js
* refactor: move properties to constructor in flyout_base.js
* refactor: move properties to constructor in flyout_button.js
* refactor: move properties to constructor in generator.js
* refactor: move properties to constructor in grid.js
* refactor: move properties to constructor in input.js
* refactor: move properties to constructor in mutator.js
* refactor: move properties to constructor in scrollbar.js
* refactor: move properties to constructor in trashcan.js
* refactor: move properties to constructor in warning.js
* refactor: move properties to constructor in workspace_audio.js
* refactor: move properties to constructor in workspace_drag_surface_svg.js
* refactor: move properties to constructor in workspace_svg.js
* refactor: move properties to constructor in workspace.js
* refactor: move properties to constructor in zoom_controls.js
* chore: rebuild
* refactor: convert zoom_controls.js to es6 class and format
* refactor: convert workspace_audio.js to es6 class and format
* refactor: convert workspace_dragger.js to es6 class and format
* refactor: convert workspace_drag_surface_svg.js to es6 class and format
* refactor: convert variable_model.js to es6 class and format
* refactor: convert variable_map.js to es6 class and format
* refactor: convert theme.js to es6 class and format
* chore: remove bad comment