Implement Registry Database Model

[mara-schulke]

Introduces

This PR introduces the database binding code for the following Models:

• pub struct User
• pub struct UserToken
• pub enum PackageType
• pub struct Package
• pub struct PackageOwner
• pub struct PackageInvite

[mara-schulke]

Will do, glad to hear 😊

[mara-schulke]

cc @xfbs for the Schema!

I mostly wrote the rust bindings here. I agree that we should fix a couple of things about it 😊

[mara-schulke]

@qsantos do you have resources to take this over?

[mara-schulke]

Re: id columns @NiklasRosenstein I would favor having them over using things like names etc. Using unique names could make renaming very hard, even if they are supposed to be static.