Add SwiftUI properties sort

[miguel-jimenez-0529]

Summary

This PR adds the SwiftUI property declaration sort rule to the style guide.

Reasoning

its preferred that SwiftUI properties are sorted by their dynamic property type. The order is determined by the first time a type appears:

    // WRONG
    struct CustomSlider: View {

      @Binding private var value: Value
      @State private var foo = Foo()
      @Environment(\.sliderStyle) private var style
      @State private var bar = Bar()
      @Environment(\.layoutDirection) private var layoutDirection

      private let range: ClosedRange<Double>
      private let step: Double.Stride
    }

    // RIGHT
    struct CustomSlider: View {

      @Binding private var value: Value
      @State private var foo = Foo()
      @State private var bar = Bar()
      @Environment(\.sliderStyle) private var style
      @Environment(\.layoutDirection) private var layoutDirection

      private let range: ClosedRange<Double>
      private let step: Double.Stride
    }

[miguel-jimenez-0529]

@calda I noticed there is a #something at the end of each, not sure what to add here.

[calda]

It's the name of the rule that uses the argument, so:

Suggested change

	--sortswiftuiprops first-appearance-sort
	--sortswiftuiprops first-appearance-sort #organizeDeclarations

[calda]

I'd put this lower down below the --typeorder option

[calda]

Nice!

[jqsilver]

Why not have a standardized order for property types?

[miguel-jimenez-0529]

Why not have a standardized order for property types?

@jqsilver we don't want to have a strong opinion on how folks define their modifiers but at the same time we want some consistency. This rule feels like a good balance between allowing you to define the order you want but ensuring a consistent order.