Issue #2915784 by dawehner, drpal, justafish, tedbow, xjm: 1/3 JS codestyle: camelcase

core/misc/machine-name.es6.js

core/misc/machine-name.js

core/misc/vertical-tabs.es6.js

core/misc/vertical-tabs.js

core/modules/block/js/block.admin.es6.js

core/modules/block/js/block.admin.js

core/modules/block/js/block.es6.js

core/modules/block/js/block.js

...ules/content_translation/content_translation.admin.es6.js

.../modules/content_translation/content_translation.admin.js

core/modules/editor/js/editor.es6.js

core/modules/editor/js/editor.js

core/modules/menu_ui/menu_ui.es6.js

core/modules/menu_ui/menu_ui.js

core/themes/bartik/color/preview.es6.js

core/themes/bartik/color/preview.js