Enable and fix some more clippy lints (#7426)

One can never have too many lints

crates/emath/src/align.rs

@@ -134,7 +134,7 @@ impl Align {
                 if size == f32::INFINITY {
                     Rangef::new(f32::NEG_INFINITY, f32::INFINITY)
                 } else {
-                    let left = (min + max) / 2.0 - size / 2.0;
+                    let left = f32::midpoint(min, max) - size / 2.0;
                     Rangef::new(left, left + size)
                 }
             }

crates/emath/src/rect.rs

@@ -331,8 +331,8 @@ impl Rect {
     #[inline(always)]
     pub fn center(&self) -> Pos2 {
         Pos2 {
-            x: (self.min.x + self.max.x) / 2.0,
-            y: (self.min.y + self.max.y) / 2.0,
+            x: f32::midpoint(self.min.x, self.max.x),
+            y: f32::midpoint(self.min.y, self.max.y),
         }
     }
 

crates/emath/src/smart_aim.rs

@@ -43,7 +43,7 @@ pub fn best_in_range_f64(min: f64, max: f64) -> f64 {
 
     if min_exponent.floor() != max_exponent.floor() {
         // pick the geometric center of the two:
-        let exponent = (min_exponent + max_exponent) / 2.0;
+        let exponent = f64::midpoint(min_exponent, max_exponent);
         return 10.0_f64.powi(exponent.round() as i32);
     }
 

crates/emath/src/ts_transform.rs

@@ -36,8 +36,8 @@ impl TSTransform {
     /// `(0, 0)`, then translates them.
     pub fn new(translation: Vec2, scaling: f32) -> Self {
         Self {
-            translation,
             scaling,
+            translation,
         }
     }