Add crash detection and report uploading on Linux

[lnihlen]

Purpose and motivation

This started as an investigation into the intermittent crash #115 and how I might be able to get better crash data and has since mushroomed into a system to ingest crash reports, with user consent, from any crashing scinsynth in production. This adds a compile-time dependency to the Crashpad client, which is compiled and installed in the separate crashpad-ext repository, like many other scinserver dependencies.

Implementation

Adds a src/infra/CrashReporter client which will launch an external monitoring process, the crash_handler binary included as part of the Crashpad build. This binary will monitor the scinserver process and if it crashes it will create a crash report, mostly including the call stack of every thread running, and deposit the data as a minidump file in the crash database. This file database is configured to live in the .crash_reports directory inside of the Scintillator quark root folder.

Adds OSC commands and some supporting sclang code to allow users to enumerate the crash reports in the database and upload individual reports or all unuploaded reports. Adds some discussion of the potential privacy implications of the reports along with documentation about how to upload the reports.

Types of changes

• Enhancement
• Documentation

Status

• This PR is ready for review
• Unit tests added
• Unit tests are passing