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/trie/src/node_codec.rs

@@ -19,9 +19,10 @@
 
 use super::node_header::{NodeHeader, NodeKind};
 use crate::{error::Error, trie_constants};
+use alloc::{borrow::Borrow, vec::Vec};
 use codec::{Compact, Decode, Encode, Input};
+use core::{marker::PhantomData, ops::Range};
 use hash_db::Hasher;
-use sp_std::{borrow::Borrow, marker::PhantomData, ops::Range, vec::Vec};
 use trie_db::{
 	nibble_ops,
 	node::{NibbleSlicePlan, NodeHandlePlan, NodePlan, Value, ValuePlan},
@@ -30,7 +31,7 @@ use trie_db::{
 
 /// Helper struct for trie node decoder. This implements `codec::Input` on a byte slice, while
 /// tracking the absolute position. This is similar to `std::io::Cursor` but does not implement
-/// `Read` and `io` is not in `sp-std`.
+/// `Read` and `io` are not in `core` or `alloc`.
 struct ByteSliceInput<'a> {
 	data: &'a [u8],
 	offset: usize,