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/externalities/Cargo.toml

@@ -19,9 +19,8 @@ targets = ["x86_64-unknown-linux-gnu"]
 [dependencies]
 codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false }
 environmental = { version = "1.1.3", default-features = false }
-sp-std = { path = "../std", default-features = false }
 sp-storage = { path = "../storage", default-features = false }
 
 [features]
 default = ["std"]
-std = ["codec/std", "environmental/std", "sp-std/std", "sp-storage/std"]
+std = ["codec/std", "environmental/std", "sp-storage/std"]

substrate/primitives/externalities/src/extensions.rs

@@ -23,10 +23,12 @@
 //! It is required that each extension implements the [`Extension`] trait.
 
 use crate::Error;
-use sp_std::{
-	any::{Any, TypeId},
+use alloc::{
 	boxed::Box,
 	collections::btree_map::{BTreeMap, Entry},
+};
+use core::{
+	any::{Any, TypeId},
 	ops::DerefMut,
 };
 

substrate/primitives/externalities/src/lib.rs

@@ -25,11 +25,10 @@
 //!
 //! This crate exposes the main [`Externalities`] trait.
 
-use sp_std::{
-	any::{Any, TypeId},
-	boxed::Box,
-	vec::Vec,
-};
+extern crate alloc;
+
+use alloc::{boxed::Box, vec::Vec};
+use core::any::{Any, TypeId};
 
 use sp_storage::{ChildInfo, StateVersion, TrackedStorageKey};