Better Parameterisation for Fee system (#3823)

* Better fee parameters

* Fix build

* Better runtime tests

* Price to Weight ratio as type parameter (#3856)

* Price to Weight ration as type parameter

* Kian feedback

* Some renames.

* Fix executor tests

* Getting Closer.

* Phantom Data

* Actually fix executor tests.

* Fix tests.

* Remove todo

* Fix build

substrate/core/sr-arithmetic/src/biguint.rs

@@ -21,7 +21,7 @@ use rstd::{cmp::Ordering, ops, prelude::*, cell::RefCell, convert::TryFrom};
 
 // A sensible value for this would be half of the dword size of the host machine. Since the
 // runtime is compiled to 32bit webassembly, using 32 and 64 for single and double respectively
-// should yield the most performance. TODO #3745 we could benchmark this and verify.
+// should yield the most performance.
 /// Representation of a single limb.
 pub type Single = u32;
 /// Representation of two limbs.

substrate/core/sr-arithmetic/src/fixed64.rs

@@ -48,6 +48,12 @@ impl Fixed64 {
 		DIV
 	}
 
+	/// Consume self and return the inner value.
+	///
+	/// This should only be used for testing.
+	#[cfg(any(feature = "std", test))]
+	pub fn into_inner(self) -> i64 { self.0 }
+
 	/// Raw constructor. Equal to `parts / 1_000_000_000`.
 	pub fn from_parts(parts: i64) -> Self {
 		Self(parts)