refactor blocks (DSL more explicit)

app/models/communication/block/component/number.rb

app/models/communication/block/template/base.rb

app/models/communication/block/template/call_to_action.rb

...els/communication/block/template/call_to_action/button.rb

app/models/communication/block/template/chapter.rb

app/models/communication/block/template/datatable.rb

app/models/communication/block/template/datatable/row.rb

...els/communication/block/template/definition/definition.rb

app/models/communication/block/template/embed.rb

app/models/communication/block/template/gallery/image.rb

app/models/communication/block/template/image.rb

app/models/communication/block/template/key_figure/figure.rb

app/models/communication/block/template/page.rb

app/models/communication/block/template/post.rb

...s/communication/block/template/testimonial/testimonial.rb

app/models/communication/block/template/timeline/timeline.rb

app/models/communication/block/template/video.rb

.../communication/blocks/components/layout/_preview.html.erb

.../communication/blocks/components/option/_preview.html.erb

...n/communication/blocks/components/option/_static.html.erb