Allow using BTreeSet, HashSet as `Value`

[ctron]

Motivation

Using PgFunc::any() requires a Vec. Since it requires an Into<SimpleExpr>, which is provided for Into<Value>.

However, having a BTreeSet or HashSet isn't supported.

Proposed Solutions

An easy way should be to implement From<BTreeSet<T>> (and HashSet) similar to the Vec<T> implementation.

More ideal would be to have this for IntoIterator<Item=T>. But I'm not sure this is feasible.

Additional Information

[tyt2y3]

That's a good idea. Two ideas on implementation in mind:

1. we can implement this entirely in SeaORM's eq_any function, having a special trait bound for it
2. we can add a wrapper type IntoArrayValue that will handle the conversion