Resolve #3479498 "Cta section variants"

Closes #3479498

• Overhauls the CTA Section component to make it more intuitive, simple, and versatile.
• Note that there are also changes to comparison cards that snuck into this MR somehow. The BEM convention has been updated to reflect that we are using dashes rather than underscores. I had to clean them up because they use the checkboxes field, so it's probably fine that it's here.

Testing steps

• On the drupalorg main project checkout to this MR branch https://gitlab.com/drupal-infrastructure/sites/drupalorg/-/merge_requests/67
• On the drupalorg contrib module project checkout out to https://www.drupal.org/project/drupalorg/issues/3487058
• composer install
• composer recreate
• visit the mothernode and verify that you can see all 3 cta section variants and that they match the designs (plus currently understood considerations)
• verify styles look good at various screen widths.
• visit storybook
• verify that you can see the CTA section component with 3 variants, and that each is rendering as expected.
• Create some test CTA section content and create some test content.
• Test the various setting and permutations/combinations.
• Is the help text helpful enough?
• Is the component create form easy enough to follow and understand?