chore: tidy code

source/components/datatable/columnbar.mjs

source/components/datatable/dataset.mjs

source/components/datatable/datasource/dom.mjs

source/components/datatable/datasource/rest.mjs

source/components/datatable/datatable.mjs

source/components/datatable/datatable/header.mjs

source/components/datatable/filter.mjs

source/components/datatable/filter/date-range.mjs

source/components/datatable/filter/input.mjs

source/components/datatable/filter/range.mjs

source/components/datatable/filter/settings.mjs

source/components/datatable/pagination.mjs

source/components/datatable/util.mjs

source/components/form/action-button.mjs

source/components/form/api-button.mjs

source/components/form/button-bar.mjs

source/components/form/confirm-button.mjs

source/components/form/form.mjs

source/components/form/message-state-button.mjs

source/components/form/popper-button.mjs