Overhaul type parsers

Prerequisite for #6290 @janmeier Can you do this? I think it’s your code

Library support:

• pg: connection-level, reference: https://github.com/brianc/node-postgres/pull/679
• mysql: query-level, reference: https://github.com/mysqljs/mysql#type-casting
• tedious ?
• sqlite ?

The benefit of query-level type parsers are that parse() can be an instance method of the data type.

[felixfbecker]

I guess it’s fine as long as we have options defined on the prototype. So basically do we agree on

• removing parserStore
• making parse() an instance method ?

For the postgres parsers I propose we just leave them at the default and then call our parsers on top of it.

[felixfbecker]

nice, if you take these, I will do the custom type parsers.