Fix some structs

[kpcyrd]

There are a few shortcomings that should be fixed before the next release:

• [x] accounts should have a phonenumber field
• [ ] devices should have location fields for locations that aren't tied to a network struct (see also #116)
• [x] domains, subdomains and emails should be lowercased automatically
• [x] accounts should have a profile picture field that points to an image blob
• [x] accounts should have a birthday field
• [x] networks should have a description field
• [ ] devices should have a first_seen field (?)