feat: add a function for retrieving the module list from a minidump

[nornagon]

Builds off #32.

[ckerr]

Minor nits inline, but overall LGTM.

I hadn't seen binary struct unpacking into JS via Node buffer before. This is disgusting and beautiful. 🙂

[nornagon]

FWIW if I were going further with this, I'd use something to help keep track of structure sizes. I wanted to avoid adding a dependency, but I've used https://github.com/Keichi/binary-parser in the past with some success. Could potentially add a super-simple version of that as a preamble :)

For now though I'm only adding this because I want to get access to the PDB file names + identifiers, and this was just enough parsing to get those. My next plan is to add code to electron-minidump that downloads the relevant PDBs from microsoft's symbol store.