Something like pgx.StrictStructArgs`Slic`

**Is your feature request related to a problem? Please describe.**

In sqlx using `NamedQuery` in an INSERT statement, you can pass in an slic of structs with `db` tags and it would go though each element in the array and append the `VALUES (..)`

**Describe the solution you'd like**
Could this be done in pgx?

**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features you've considered.

**Additional context**
Add any other context or screenshots about the feature request here.

No file or test is named. Start by reviewing pgx's existing StrictStructArgs and query-building APIs, then compare the requested behavior with sqlx's NamedQuery handling of slices of tagged structs. Done would mean a defined pgx-supported way to expand such a slice into INSERT VALUES arguments.

Written by the indexing model from the issue text.