paragraphs_bundles 2.0.1

Bug-fix release for sites upgrading from 1.x. Run `drush updatedb` after updating.

Fixed
- #3629036: two- and three-column sections created before 1.0.17 can be edited and saved again. 1.0.17 made "Toggle animation effect" required without filling it on existing sections, so saving those pages failed with "Toggle animation effect field is required". An update fills the missing value with "slide" (how those sections already displayed, so no page changes) on the current version and every revision. A value you already chose is kept. Thanks shank115 for the first patch.
- 3D carousel: the 1.x CSS class paragraph--type--3d-carousel-bundle is back. 2.0.0 printed paragraph--type--_d-carousel-bundle instead; both are printed now, so themes written for either release keep working.
- Upgraded sites get the 2.x names "Lightbox Gallery" and "Lightbox Image" for the image grid sections, and the help text for the Simple section's border, border radius, margin, padding and shadow fields and Image Background's padding field. A name or help text you changed yourself is kept. Translated names and help text stay as they were; update those by hand.

Documentation
- CSS-CLASS-MIGRATION.md lists 14 more 1.x classes the 2.0.0 edition missed, including js-pb-close-alert and the column toggle icon classes.

Tested on a real 1.0.18 site using all 39 section types, upgraded to 2.0.1: every page loads, every edit form saves, and no content was lost.