tests

Add Postgre function: `DATE_TRUNC` #2282

Job	Run time
Build `sea-query-postgres`	41s
Clippy	53s
Build `sea-query-binder` (async-std, rustls)	2m 2s
Build `sea-query`	43s
Rustfmt	17s
Build `sea-query-rusqlite`	41s
Derive Tests	49s
Unit Test	2m 0s
Any	59s
MariaDB (10.6, sqlx_mysql)	1m 9s
MySQL (8, sqlx_mysql)	1m 22s
PostgreSQL (14.4, postgres)	47s
MySQL (5.7, sqlx_mysql)	1m 22s
PostgreSQL (14.4, sqlx_postgres)	1m 11s
SQLite (rusqlite)	20s
PostgreSQL (13.7, postgres)	46s
SQLite (sqlx_sqlite)	50s
PostgreSQL (13.7, sqlx_postgres)	1m 17s
PostgreSQL (12.11, postgres)	44s
PostgreSQL (12.11, sqlx_postgres)	1m 13s
	20m 6s

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