PhragMMS election. (#6685)

* Revamp npos-elections and implement phragmms

* Update primitives/npos-elections/src/phragmms.rs

* Fix build

* Some review grumbles

* Add some stuff for remote testing

* fix some of the grumbles.

* Add remote testing stuff.

* Cleanup

* fix docs

* Update primitives/arithmetic/src/rational.rs

Co-authored-by: Dan Forbes <dan@danforbes.dev>

* Small config change

* Better handling of approval_stake == 0

* Final touhces.

* Clean fuzzer a bit

* Clean fuzzer a bit

* Update primitives/npos-elections/src/balancing.rs

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

* Fix fuzzer.

* Better api for normalize

* Add noramlize_up

* A large number of small fixes.

* make it merge ready

* Fix warns

* bump

* Fix fuzzers a bit.

* Fix warns as well.

* Fix more tests.

Co-authored-by: Dan Forbes <dan@danforbes.dev>
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

substrate/Cargo.lock

@@ -2205,9 +2205,9 @@ dependencies = [
 
 [[package]]
 name = "honggfuzz"
-version = "0.5.49"
+version = "0.5.51"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "832bac18a82ec7d6c21887daa8616b238fe90d5d5e762d0d4b9372cdaa9e097f"
+checksum = "6f085725a5828d7e959f014f624773094dfe20acc91be310ef106923c30594bc"
 dependencies = [
  "arbitrary",
  "lazy_static",