Shooting and sharing a photo directly from chat

[audax]

In addition to #746, I want to make a photo and send it directly from the chat.

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When I am in a chat with a contact
I want to start the camera application directly from the chat
And if I create a photo in that camera application
Then the photo should be uploaded to a default folder
And it should be shared to my conversation partner.

[audax]

Depends on #793

[enkore]

• After taking the photo a preview should be displayed. The upload must be confirmed by the user.
• If possible minimize local interaction. Try to avoid the possibility of the picture being synced to big G

[thechauffeur]

Prior to directly uploading after capturing the photo the user should get a preview of the photo and decide if it should be uploaded.

[enkore]

See #796 for follow-up.