Central extension point for the view is 'io.ox/mail/compose/sharing' now. So almost every extension references the old point has to be adjusted.

- main view: 'attachmentPreview' of 'io.ox/mail/compose/view.js'
- extension: 'attachmentSharing' of 'io.ox/mail/compose/extensions.js'
- share attachment view: 'io.ox/mail/compose/sharing'

Also ui defaults for the different settings/configs (io.ox/mail//compose/shareAttachments/) are now defined server side.
Please take a look at 'io.ox/mail/compose/sharing' for details.

On the ux side the currently enabled expire option is shown as part of the dropdown label and the 'remove after expire' option is hidden when
'no expire' option is selected.

related commits:
c4e3fc7733e52653dd432d29565717dec24076ab
47debb99c37e05eb85b33dc9910caf3fc572195a
3ffcad03ef1500f69d437390c0490146b00f5056
246d703223f9413be119223968b19addab4bb6e1
f7f2f13aef1369c422f403eca636730d7295e858
c532e693a9982a94ef7ea8c58ab25b7572301350
4d70e07afed7b907f3c31c4bb20ec773feea1864
39d25991bc4b44caff67e676c510b04f7a1abdc1
0485cef26fc9ef43588b5966288cb2734c81e7d0