Change "model" property from string to object in @prismaRelation decorator

[juliano-soares]

Description:
Currently, the @prismaRelation decorator uses a string to specify the related model in the Prisma schema. For example:

Before:

@prismaField({ type: Profile })
@prismaRelation({
    relation: Relation.OneToOne,
    model: "Profile",
    refs: ["id"],
    onDelete: Action.Cascade,
    onUpdate: Action.Cascade,
})
profile!: Profile;

Proposal:
I suggest changing the model property from a string to an object reference of the related model. This would improve type safety and make it consistent with how Prisma handles relations in the schema.

After:

@prismaField({ type: Profile })
@prismaRelation({
    relation: Relation.OneToOne,
    model: Profile, // <- Here
    refs: ["id"],
    onDelete: Action.Cascade,
    onUpdate: Action.Cascade,
})
profile!: Profile;

This change will not only enhance the readability of the code but also provide better TypeScript support, as it allows proper type checking and autocompletion when defining relations.