feat: Parse minidump crashpad metadata

[timfish]

• Closes Attach information from minidumps as contexts before they are sent to Sentry #1094

This PR adds parsing to pull annotations from the crashpad stream in the loaded minidumps and include them in the event context.

Electron includes additional v8 context in the crashpad metadata (like electron.v8-oom.detail which gives details about the OOM reason):
https://github.com/electron/electron/blob/d987bee0073310c0bf114dd5e5c9db5e9c68ee59/shell/common/node_bindings.cc#L193
This PR reads that data from the minidump and includes it in the electron context and prepends the keys with crashpad.. This allows users to use this info in beforeSend filters and in other sampling decisions.

The parser code was mostly aided by the rust-minidump crate which has great documentation but I've credited it fully in the source because it would have been a lot more complicated without such a comprehensive library to test against.

I still want to add:

• Unit tests with sample minidumps