Before this, the "X" button resets to the original (previous) publish date for Edits, and resets to current time for New Claims. This is very confusing, so added explicit text-based buttons -- hopefully this is more intuitive.
- `releaseTime` is now a number instead of a string, matching `release_time`. It was getting confusing what the variable units were.
- `releaseTime` will always match `release_time` for an edit. It will be used in the GUI to reset just the date to the original, instead of having to reset the entire form.
- `releaseTimeEdited` will be used by `updatePublishForm` in the GUI to represent the desired new release time. Set to `undefined` if we don't want to change the date.
- Use white color for calendar buttons in release date input
- Update icon color for release date input
- Allow to set time in release date and display it under additional options
- Add release date field
