Improve and document existing alcotests

Status	Subdirectory in `src/`	MR	Branch	Remark
✅	`lib_micheline`	!2113 (merged)	`hai@alcotests-documentation-lib_micheline`
✅	`lib_shell`	!2102 (merged)	`hai@tezos-alcotests-documentation-lib_shell`	Rebased on `store_rehaul`. Waiting for @vbotbol
✅	`proto_alpha/lib_protocol`	!2400 (merged) !318 (closed)	`hai@alcotests-documentation-lib_protocol_rebased_metastatedev_upon_proto-proposal`	On hold. Waiting for @paracetamolo
✅	`proto_alpha/lib_client`	!2154 (merged)	`hai@alcotests-documentation-lib_client`
	`lib_storage`		`hai@tezos-alcotests-documentation-lib_shell`	Rebased on `store_rehaul`. Waiting for @vbotbol
✅	`lib_signer_backends`	!2145 (merged)	`hai@alcotests-documentation-lib_signer_backends`
✅	`lib_error_monad`	!2141 (merged)	`hai@alcotests-documentation-lib_error_monad`
🚫	`lib_stdlib`			To be externalized by @raphael-proust.
🚫	`lib_stdlib_unix`			To be externalized by @raphael-proust.
✅	`lib_requester`	!2147 (merged)	`hai@alcotests-documentation-lib_requester`
🚫	`bin_client`			Not an alcotest.
🚫	`lib_lwt_result_stdlib`			To be externalized by @raphael-proust.
✅	`lib_client_base`	!2146 (merged)	`hai@alcotests-documentation-lib_client_base`
✅✅	`lib_p2p`	!2115 (merged) !2192 (merged)	`hai@alcotests-documentation-lib_p2p`
✅	`lib_crypto`	!2109 (merged)	`hai@alcotests-documentation-lib_crypto`
✅	`lib_protocol_environment`	!2142 (merged)	`hai@alcotests-documentation-lib_protocol_environment`

Legend:

🚫 : nothing to be done
🚧 : work-in-progress
🔄 : to be reviewed
🚦 : on hold
✅ : merged

Guidelines

See Tezos Developer Resources > Testing > Conventions

Tests to fix

Here is the list of, presumably, test files (obtained through find src -path \*test/\*.ml). I've removed the tests from protocol Carthage. Some of these may not be actual test files but helpers, however, incoherent naming makes it difficult to know without inspecting each file.

Edited Feb 02, 2021 by Hai Nguyen Van