Extend VeraCrypt automated tests with PIM

On Tails/Buster we have a recent enough cryptsetup that allows us to use the VeraCrypt PIM feature. So let’s extend our test suite to exercise this.

I’ll write the initial VeraCrypt tests in a way that makes it easy to do this.

Feature Branch: test/15946-veracrypt-tests-with-pim

Original created by @intrigeri on 15946 (Redmine)

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