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/primitives/crypto/ec-utils/src/bls12_377.rs

@@ -18,10 +18,10 @@
 //! *BLS12-377* types and host functions.
 
 use crate::utils;
+use alloc::vec::Vec;
 use ark_bls12_377_ext::CurveHooks;
 use ark_ec::{pairing::Pairing, CurveConfig};
 use sp_runtime_interface::runtime_interface;
-use sp_std::vec::Vec;
 
 /// First pairing group definitions.
 pub mod g1 {