Validations, Space Template fixes, other bug fixes
- Fixes an issue where badly formed entries created via the API would prevent editing them in the UI
- Fixes an issue where images that can't be cropped for previewing would still be displayed
- Adds support to validate the number of Entries, Assets, or Symbols in a List.
- Adds support for date, file size, and image dimension validations
- Adds support for multiple file type validation.
- Content Type editors can now provide custom error messages for all enabled validations.