`FromRow` does not allow to derive immutable references in its structures

[Luni-4]

Is your feature request related to a problem? Please describe.

Until now it is not possible to obtain immutable shared references deriving FromRow

#[derive(FromRow, Serialize, Deserialize)]
struct Foo<'r> {
    /// Name
    name: &'r str,
}

This behaviour would be really helpful when you have to read data contained in a structure without the necessity to modify anything. This also avoid further allocations when passing around the structure or inserting new data.

I have to admit that I have not analyzed the feasibility of this feature, therefore please close this issue whether it is deemed infeasible.

Describe the solution you'd like

Allow immutable references in FromRow derived-structures

[qsantos]

Related: https://github.com/launchbadge/sqlx/issues/2661