Let `last_insert_id` optional and flexible. #4467

Job	Run time
Init	6s
Rustfmt	18s
Examples (examples/actix_example)	2m 29s
Clippy	23s
Examples (examples/axum_example)	2m 28s
Unit Test	3m 23s
Examples (examples/basic)	1m 11s
Examples (examples/graphql_example)	2m 43s
Examples (examples/jsonrpsee_example)	2m 39s
Examples (examples/loco_example)	2m 49s
Examples (examples/loco_starter)	3m 0s
Examples (examples/loco_seaography)	4m 7s
Examples (examples/poem_example)	2m 44s
Examples (examples/proxy_gluesql_example)	1m 30s
Examples (examples/react_admin)	3m 57s
Examples (examples/rocket_example)	3m 7s
Examples (examples/rocket_okapi_example)	3m 27s
Examples (examples/salvo_example)	2m 43s
Examples (examples/seaography_example)	2m 29s
Examples (examples/tonic_example)	2m 36s
Compile PostgreSQL (tokio, native-tls)	3m 1s
Compile SQLite (async-std, native-tls)	2m 59s
Compile PostgreSQL (tokio, rustls)	3m 19s
Compile MySQL (actix, native-tls)	2m 47s
Compile SQLite (async-std, rustls)	2m 54s
CLI	0s
Compile MySQL (actix, rustls)	3m 20s
Issues Matrix	0s
Issues	0s
MariaDB (lts, actix, native-tls)	2m 24s
MySQL (lts, actix, native-tls)	3m 30s
MySQL (5.7, actix, native-tls)	3m 30s
Postgres (14, tokio, native-tls)	6m 46s
Postgres (16, tokio, native-tls)	6m 46s
SQLite (async-std, native-tls)	4m 19s
SQLite (async-std, rustls)	4m 34s
	1h 38m 18s

Provide feedback