Add snake case support to RowToStructByName

[ghost]

RowToStructureByName doesn't support the conversion of snake_case to PascalCase, which is used in Go.

[jackc]

• It looks like this broken existing tests / behavior.
• It would be good to have tests for this new behavior?
• Is the kebab-case support necessary? That is only possible in PostgreSQL if using double-quotes around the identifiers. I've never actually seen it in the wild.

[ghost]

• It looks like this broken existing tests / behavior.
• It would be good to have tests for this new behavior?

Yeah, I didn't think that small changes would break anything. It's looks like this is happening because of the struct tags, I'll fix it

• Is the kebab-case support necessary? That is only possible in PostgreSQL if using double-quotes around the identifiers. I've never actually seen it in the wild.

No, I don't think so. I've never seen it too 😃

[jackc]

I'll merge this as is.

I am slightly concerned about performance as this adds two string allocations for every assignment. But I think there is already some reflection in that path so it might not matter.