The DeriveActiveModel derive macro will implement ActiveModelTrait for ActiveModel
which provides setters and getters for all active values in the active model.
The DeriveColumn derive macro will implement [ColumnTrait] for Columns.
It defines the identifier of each column by implementing Iden and IdenStatic.
The EnumIter is also derived, allowing iteration over all enum variants.
The DeriveModel derive macro will implement ModelTrait for Model,
which provides setters and getters for all attributes in the mod
It also implements FromQueryResult to convert a query result into the corresponding Model.
The DerivePrimaryKey derive macro will implement [PrimaryKeyToColumn]
for PrimaryKey which defines tedious mappings between primary keys and columns.
The [EnumIter] is also derived, allowing iteration over all enum variants.