Tidy up core pattern.mjs

[yaxu]

Mainly I have in mind to make sure all pattern methods have equivalent module functions and vice-versa, while removing redundancy.

[yaxu]

Things are a bit tidier with #274

But there's still a lot of mess. Howabout we make the Pattern class barebones, and build it up dynamically? A function addMethod could take care of adding the method, and optionally patternifying one or more arguments, adding a toplevel module function that's curried and with the pattern as the final argument, etc.

This already mostly exists as Pattern.prototype.define, why not use that for everything?

Then it'd be easy to switch to having the Pattern object be the query function, if we wanted.

[yaxu]

Things have moved on, so closing this. We can make more specific issues in the future..