frame: GenesisBuild::build allowed in no_std (#14107)

* frame: GenesisBuild::build allowed in no_std

i`GenesisBuild::build` function will be required for no_std in no native
runtime world.

`GenesisBuild::build` macro generated function allows to build the runtime
GenesisConfig assembled from all pallets' GenesisConfigs.

* fixes

* GenesisBuild::build avaiable in no-std

- #[cfg(feature = "std")] is not longer added to GenesisBuild implementation.

* system: hash69 available for no-std

* elections-phragmen: panic message fixed for no_std

* frame::suport: doc updated

* test-runtime: default for GenesisConfig

* frame::test-pallet: serde/std added to std feature deps

* Cargo.toml: deps sorted

* Cargo.lock update

cargo update -p frame-support-test-pallet -p frame-support-test

* frame ui tests: cleanup

---------

Co-authored-by: parity-processbot <>

substrate/frame/support/test/pallet/Cargo.toml

@@ -14,6 +14,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 [dependencies]
 codec = { package = "parity-scale-codec", version = "3.2.2", default-features = false, features = ["derive"] }
 scale-info = { version = "2.0.0", default-features = false, features = ["derive"] }
+serde = { version = "1.0.136", default-features = false, features = ["derive"] }
 frame-support = { version = "4.0.0-dev", default-features = false, path = "../../" }
 frame-system = { version = "4.0.0-dev", default-features = false, path = "../../../system" }
 
@@ -24,4 +25,5 @@ std = [
 	"frame-support/std",
 	"frame-system/std",
 	"scale-info/std",
+	"serde/std",
 ]