Let `last_insert_id` optional and flexible. #4474

Job	Run time
Rustfmt	16s
Clippy	1m 21s
Examples (examples/actix_example)	2m 29s
Init	4s
Examples (examples/axum_example)	2m 25s
Unit Test	3m 14s
Examples (examples/basic)	1m 15s
Examples (examples/graphql_example)	2m 45s
Examples (examples/jsonrpsee_example)	2m 41s
Examples (examples/loco_example)	2m 52s
Examples (examples/loco_starter)	2m 59s
Examples (examples/loco_seaography)	3m 53s
Examples (examples/poem_example)	2m 22s
Examples (examples/proxy_gluesql_example)	1m 6s
Examples (examples/react_admin)	3m 45s
Examples (examples/rocket_example)	2m 59s
Examples (examples/rocket_okapi_example)	3m 14s
Examples (examples/salvo_example)	2m 46s
Examples (examples/seaography_example)	2m 31s
Examples (examples/tonic_example)	2m 29s
Compile PostgreSQL (tokio, native-tls)	3m 0s
Compile PostgreSQL (tokio, rustls)	3m 5s
Compile SQLite (async-std, native-tls)	2m 48s
Compile MySQL (actix, native-tls)	2m 50s
Compile SQLite (async-std, rustls)	3m 1s
CLI	0s
Compile MySQL (actix, rustls)	2m 57s
Issues Matrix	0s
Issues	0s
Postgres (14, tokio, native-tls)	6m 59s
Postgres (16, tokio, native-tls)	6m 46s
SQLite (async-std, native-tls)	4m 21s
SQLite (async-std, rustls)	4m 26s
MariaDB (lts, actix, native-tls)	2m 33s
MySQL (lts, actix, native-tls)	3m 29s
MySQL (5.7, actix, native-tls)	3m 24s
	1h 37m 5s

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