Fix has expiration date logic

Fix has expiration date logic

Current expiration date errorneously assumes that `defaultExpirationDate`
applies to all kinds of shares. But it only really applies to public shares despite
its name.

This commit, fixes that by paring expiration dates with the correct share types during
new share initialization and simplifying the `hasExpirationDate` (check) property.

Signed-off-by: fenn-cs <fenn25.fn@gmail.com>