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/timestamp/Cargo.toml

@@ -21,7 +21,6 @@ codec = { package = "parity-scale-codec", version = "3.6.1", default-features =
 thiserror = { optional = true, workspace = true }
 sp-inherents = { path = "../inherents", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 
 [features]
 default = ["std"]
@@ -30,6 +29,5 @@ std = [
 	"codec/std",
 	"sp-inherents/std",
 	"sp-runtime/std",
-	"sp-std/std",
 	"thiserror",
 ]