feat: add `copy_*e_to_slice` family #977

Job	Run time
Clippy	50s
Docs	47s
Feature checks	1m 24s
Fmt	12s
test (stable, --no-default-features)	1m 34s
Cargo deny check	21s
test (stable)	1m 34s
test (stable, --all-features)	2m 11s
test (beta, --no-default-features)	1m 30s
test (beta)	1m 27s
test (beta, --all-features)	2m 21s
test (nightly, --no-default-features)	53s
test (nightly)	52s
test (nightly, --all-features)	2m 1s
test (1.65, --no-default-features)	26s
test (1.65)	21s
Accept	0s
	18m 44s

Provide feedback