sp-std removal from substrate/primitives (#3274)

This PR removes sp-std crate from substrate/primitives sub-directories.

For now crates that have `pub use` of sp-std or export macros that would
necessitate users of the macros to `extern crate alloc` have been
excluded from this PR.

There should be no breaking changes in this PR.

---------

Co-authored-by: Koute <koute@users.noreply.github.com>

substrate/test-utils/runtime/src/lib.rs

@@ -19,6 +19,8 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 #[cfg(feature = "std")]
 pub mod extrinsic;
 #[cfg(feature = "std")]
@@ -42,9 +44,10 @@ use frame_system::{
 	CheckNonce, CheckWeight,
 };
 use scale_info::TypeInfo;
-use sp_std::prelude::*;
+
+use alloc::boxed::Box;
 #[cfg(not(feature = "std"))]
-use sp_std::vec;
+use alloc::{vec, vec::Vec};
 
 use sp_application_crypto::{ecdsa, ed25519, sr25519, RuntimeAppPublic};
 use sp_core::{OpaqueMetadata, RuntimeDebug};
@@ -265,7 +268,7 @@ impl sp_runtime::traits::SignedExtension for CheckSubstrateCall {
 
 	fn additional_signed(
 		&self,
-	) -> sp_std::result::Result<Self::AdditionalSigned, TransactionValidityError> {
+	) -> core::result::Result<Self::AdditionalSigned, TransactionValidityError> {
 		Ok(())
 	}
 
@@ -440,7 +443,7 @@ fn code_using_trie() -> u64 {
 	.to_vec();
 
 	let mut mdb = PrefixedMemoryDB::default();
-	let mut root = sp_std::default::Default::default();
+	let mut root = core::default::Default::default();
 	{
 		let mut t = TrieDBMutBuilderV1::<Hashing>::new(&mut mdb, &mut root).build();
 		for (key, value) in &pairs {
@@ -494,7 +497,7 @@ impl_runtime_apis! {
 		fn metadata_at_version(_version: u32) -> Option<OpaqueMetadata> {
 			unimplemented!()
 		}
-		fn metadata_versions() -> sp_std::vec::Vec<u32> {
+		fn metadata_versions() -> alloc::vec::Vec<u32> {
 			unimplemented!()
 		}
 	}