feat: Add .apply_if to SelectStatement

[theelderbeever]

PR Info

The .apply_if method from SeaORM is 👨‍🍳 💋 in my opinion. This PR adds a similar method to the SelectStatement that can live beside .conditions as a more direct way to unpack Option type conditionals.

let query = Query::select()
    .column(Char::Character)
    .from(Char::Table)
    .apply_if(
        Some(5),
        |q, v| {
            q.and_where(Expr::col(Char::FontId).eq(v));
        }
    )
    .to_owned();

New Features

• Adds convenience function pub fn apply_if<T, F>(&mut self, val: Option<T>, if_some: F) to SelectStatement in an attempt to emulate SeaORM's .apply_if functionality.

Bug Fixes

N/A

Breaking Changes

N/A

Changes

• Adds corresponding doctest

[tyt2y3]

Thank you!

[theelderbeever]

@tyt2y3 Saw the doctest failed on formatting so just pushed the fix.