Support encrypting for multiple recipients (and add Scala 3 support)

[bpholt]

In order to add support for Scala 3, we need to update to Refined 0.11 and swap out Shapeless tagged types with a Scala-3 compatible library like Monix Newtypes. Since that all requires making changes to the ABI, it's a good opportunity to remove a lot of bincompat cruft that had built up, and also make the core algebras available independently. This omnibus PR does all of that.

I'm working on Scalafixes for the source-breaking changes, so hopefully we can have those ready for Scala Steward to run before this is released as v0.5.0.

[bpholt]

@CJSmith-0141 can you take a look and let me know what you think, or if you have any questions?

[CJSmith-0141]

Thank you for taking this up! I'll take a look at in and provide a review / feedback / ask questions.

[CJSmith-0141]

Much more comprehensive than my attempt, thank you! +1

[bpholt]

I was thinking that I should hold off on merging this until the Scalafixes are done, but I just realized we can go ahead and merge—Scala Steward won't suggest updates until this is actually released, and we can hold off on that until the Scalafixes are ready. In the meantime, we can use the snapshot that will be published on the merge.

[CJSmith-0141]

@bpholt What are you referring to with Scalafixes? Thank you for cutting a release on the 0.4.x series.

[bpholt]

What are you referring to with Scalafixes?

e.g. a Scalafix rule to rewrite a method call from armor() to armor. I think most of the source-breaking changes introduced can be automatically rewritten, which would be nice for anyone who gets the update via Scala Steward.

Here's the list of rules I came up with:

1. CryptoAlg constructor

   CryptoAlg[F]

   to

   CryptoAlg.resource[F]

2. Armor parens

   cryptoAlg.armor()

   to

   cryptoAlg.armor

3. Encrypt options

   cryptoAlg.encrypt(key, fileName = filename.value.some)

   to

   cryptoAlg.encrypt(EncryptionConfig().withFileName(filename.value.some), key)

4. tagged types

   tagChunkSize(foo: PosInt)

   to

   ChunkSize(foo)

[CJSmith-0141]

As an FYI @bpholt I cut a release based on this branch on my fork and have been using it in Scala 3 without issue. I couldn't figure out how to keep Scala 2.12 working, so I dropped it from my fork. If there is anything I could do to get this merged here please let me know! Is it just writing some scalafix rules? Would dropping 2.12 support here be ok?