refactor: Move source map lookups to core

[nayeemrmn]

This had been blocking lots of other cleanups as well. Namely the following transformations gradually faced by JsError have all been moved up front to JsError::from_v8_exception(): finding the first non-deno: source line [old code]; moving JsError::script_resource_name etc. into the first error stack in case of syntax errors [old code]; source mapping JsError::script_resource_name etc. when wrapping the error even though the frame locations are source mapped earlier [old code]; removing JsError::{script_resource_name,line_number,start_column,end_column} entirely in favour of js_error.frames.get(0). We also no longer pass a js-side callback to core/02_error.js from cli. I avoided doing this on previous occasions because the source map lookups were in an awkward place.

[bartlomieju]

LGTM, I like how much code is getting removed. That said, I want to get some more eyes on it, as moving source mapping to core might be a bit controversial for other team members.