Region: remove Clone from the trait, and also parameterize everything

i didn't necessarily *want* to parameterize it all,
but it turned out to be easier to do that than to force all users to
workaround the lack of Clone.

crates/coremem/src/meas.rs

@@ -212,7 +212,6 @@ impl<S: AbstractSim> AbstractMeasurement<S> for Meta {
     }
 }
 
-#[derive(Clone)]
 pub struct Volume {
     name: String,
     region: Box<dyn Region>,
@@ -241,7 +240,6 @@ impl<S: AbstractSim> AbstractMeasurement<S> for Volume {
     }
 }
 
-#[derive(Clone)]
 pub struct Current {
     name: String,
     region: Box<dyn Region>,
@@ -471,7 +469,6 @@ impl<S: AbstractSim> AbstractMeasurement<S> for MagneticLoop {
 }
 
 /// mean M over a region
-#[derive(Clone)]
 pub struct MagneticFlux {
     name: String,
     region: Box<dyn Region>,
@@ -508,7 +505,6 @@ impl<S: AbstractSim> AbstractMeasurement<S> for MagneticFlux {
 }
 
 /// mean B over a region
-#[derive(Clone)]
 pub struct Magnetization {
     name: String,
     region: Box<dyn Region>,
@@ -604,7 +600,6 @@ impl<S: AbstractSim> AbstractMeasurement<S> for ElectricField {
     }
 }
 
-#[derive(Clone)]
 pub struct Energy {
     name: String,
     region: Box<dyn Region>,
@@ -648,7 +643,6 @@ impl<S: AbstractSim> AbstractMeasurement<S> for Energy {
     }
 }
 
-#[derive(Clone)]
 pub struct Power {
     name: String,
     region: Box<dyn Region>
@@ -732,7 +726,6 @@ pub mod test {
         }
     }
 
-    #[derive(Clone, Serialize, Deserialize)]
     struct MockRegion {
         normal: Vec3<f32>,
     }