Remove runtime panics from unsupported types

[kriswuollett]

Motivation

I'd like to be able to use sea-query in production without the risk of panics and crashing, by transforming panics into Result types where possible. This issue is specifically raised for incompatible data types. For example the docs say that u64 isn't supported for SQLite, but it doesn't say it will crash your app if you try using it as a query argument:

sea-query/sea-query-binder/src/sqlx_sqlite.rs

Lines 34 to 37 in 605ec44

	Value::BigUnsigned(i) => {
	let _ = args
	.add(i.map(|i| <i64 as std::convert::TryFrom<u64>>::try_from(i).unwrap()));
	}

A specific use case would be for sharing some database schema between a SQLite database embedded with a client and a server like PostgreSQL. But also lately developers have been using SQLite on the server-side as well...

Proposed Solutions

• Preprocess query arguments to make sure they are compatible with the driver before passing into sqlx::IntoArguments
• Or, return 0 arguments from sqlx::IntoArguments as a sentinel value to represent an error since it doesn't support returning a result type
• Until, and if, sqlx, supports result type from IntoArguments, see Usability improvements to Arguments, IntoArguments traits launchbadge/sqlx#3586