Allow to create internal share

[dkocher]

Currently one can only create public links. Allow to create share ¹ of type 0=user or 4=email with internal users. Requires an input field option to select the user registered. Should be possible to lookup other users using the Sharee API ².

Footnotes

1. https://docs.nextcloud.com/server/latest/developer_manual/client_apis/OCS/ocs-share-api.html#create-a-new-share ↩

2. https://docs.nextcloud.com/server/latest/developer_manual/client_apis/OCS/ocs-sharee-api.html#search-sharees ↩