fix(raftwal): Pass the encryption key instead of reading from WorkerConfig

[ahsanbarkati]

We should not read the encryption key from the worker config, rather we can pass it as an argument to the Init() method which initializes the diskStorage for the raftwal.

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[danielmai]

What if we had a func called InitEncrypted(dir string, encKey x.SensitiveByteSlice) *DiskStorage alongside the Init func? That way the change isn't as invasive as adding nil everywhere for Init(dir, nil). And, given that all the error checks just panic/stop anyway if raftwal isn't init'd when returning an error value, is returning an error helpful?

Reviewable status: 0 of 10 files reviewed, all discussions resolved (waiting on @manishrjain and @vvbalaji-dgraph)

[ahsanbarkati]

Yes, having InitEncrypted makes sense. The idea for returning the error was mainly because of the tests, we need to check against the errors in the tests. But yes, I can make Init a wrapper around InitEncrypted and handle the error there itself.

[jarifibrahim]

Remove the return parameter from InitEncrypted function and this PR should be good to merge.