Expand issue interpolation

[rwblair]

Currently we evaluate message field of a partial issue from schema. This could be expanded to location, suggestion, affects and not expanded to code, line severity, character, rule.

[effigies]

I'm kind of a toss-up on interpolating subCode. Could be useful, but I don't see an immediate use case.

Worth noting that affects is a list, which makes it a bit different from the others.