Add support for Paket

[xt0rted]

Checklist:

• If this PR is a new feature, please provide at least one example link
• Make sure all of the significant new logic is covered by tests

This adds support for the f#/.net package manager Paket. I didn't add support for paket.lock files because we don't really support them for other environments.

Example files used when building this out:

• https://github.com/fsprojects/Paket/blob/master/paket.dependencies
• https://github.com/fsharp/TryFSharp/blob/d2d4b6bee9d5b6a232c3e902f5af06eb460e3419/paket.dependencies
• https://github.com/fsprojects/Paket/blob/master/src/Paket/paket.references
• https://github.com/simontaite/EFCore.FSharp.MigrationTest/blob/ae0a7c97379ea4958bd75ebcf861fcf81538af6f/paket.local

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Original pr #1047