Weight annotation. (#3157)

* Make extrinsics extensible.

Also Remove old extrinsic types.

* Rest of mockup. Add tips.

* Fix some build issues

* Runtiem builds :)

* Substrate builds.

* Fix a doc test

* Compact encoding

* Extract out the era logic into an extension

* Weight Check signed extension. (#3115)

* Weight signed extension.

* Revert a bit + test for check era.

* Update Cargo.toml

* Update node/cli/src/factory_impl.rs

* Update node/executor/src/lib.rs

* Update node/executor/src/lib.rs

* Don't use len for weight - use data.

* Operational Transaction; second attempt (#3138)

* working poc added.

* some fixes.

* Update doc.

* Fix all tests + final logic.

* more refactoring.

* nits.

* System block limit in bytes.

* Silent the storage macro warnings.

* More logic more tests.

* Fix import.

* Refactor names.

* Fix build.

* Update srml/balances/src/lib.rs

* Final refactor.

* Bump transaction version

* Fix weight mult test.

* Fix more tests and improve doc.

* Bump.

* Make some tests work again.

* Fix subkey.

* Remove todos + bump.

* First draft of annotating weights.

* Refactor weight to u64.

* More refactoring and tests.

* New convert for weight to fee

* more tests.

* remove merge redundancy.

* Fix system test.

* Bring back subkey stuff.

* a few stress tests.

* fix some of the grumbles.

* Final nits.

* Update srml/system/src/lib.rs

Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com>

* Scale weights by 1000.

* Bump.

* Fix decl_storage test.

substrate/srml/finality-tracker/src/lib.rs

@@ -268,6 +268,7 @@ mod tests {
 	use substrate_primitives::H256;
 	use primitives::traits::{BlakeTwo256, IdentityLookup, OnFinalize, Header as HeaderT};
 	use primitives::testing::Header;
+	use primitives::Perbill;
 	use srml_support::{assert_ok, impl_outer_origin, parameter_types};
 	use srml_system as system;
 	use std::cell::RefCell;
@@ -301,6 +302,7 @@ mod tests {
 		pub const BlockHashCount: u64 = 250;
 		pub const MaximumBlockWeight: u32 = 1024;
 		pub const MaximumBlockLength: u32 = 2 * 1024;
+		pub const AvailableBlockRatio: Perbill = Perbill::one();
 	}
 	impl system::Trait for Test {
 		type Origin = Origin;
@@ -315,6 +317,7 @@ mod tests {
 		type Event = ();
 		type BlockHashCount = BlockHashCount;
 		type MaximumBlockWeight = MaximumBlockWeight;
+		type AvailableBlockRatio = AvailableBlockRatio;
 		type MaximumBlockLength = MaximumBlockLength;
 	}
 	parameter_types! {