New `kotools.types.NotEmptyList` type

[LVMVRQUXL]

Description

Create a new NotEmptyList type in the kotools.types package and deprecate the old type from kotools.types.collections.

Keep it simple by only providing its builders.

Checklist

• [x] Create type with its builders.
• [x] Make the type serializable.
• [x] Deprecate the old type.
• [x] Refactor.
• [x] Update Work in progress section in changelog.

[LVMVRQUXL]

Done.