WIP - Update sentry take 2

[brainbicycle]

Mirroring @ds300's comment from old PR here:

Need to run some more testing on this

• [ ] make sure native crashes are reported correctly
• [ ] make parallel branch for eigen
• [ ] understand and test eigen-specific crash reporting code (breadcrumbs etc?)
• [ ] investigate unhandled promise rejection reports (doesn't work in dev mode, check in a beta build if possible)

[brainbicycle]

Closing and reopening in combined repo. https://github.com/artsy/eigen/pull/3037