feat(users/Profpatsch/netencode): Add initial Haskell parser

A simple categorical parser that does not implement Monad, and does
not contain an `m` and some rudementary error message handling.

In the future I’d probably want to wrap everything in an additional
`m`, so that subparsers can somehow use `Selective` to throw errors
from within `m` that contain the parsing context if at all possible.
Hard to do without Monad, I have to say. Not even stuff like `StateT`
works without the inner `m` implementing `Monad`.

Change-Id: I1366eda606ddfb019637b09c82d8b0e30bd4e318
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7797
Tested-by: BuildkiteCI
Reviewed-by: Profpatsch <mail@profpatsch.de>

users/Profpatsch/my-prelude/my-prelude.cabal

@@ -30,6 +30,7 @@ library
      , profunctors
      , containers
      , error
+     , exceptions
      , bytestring
      , mtl
      , hspec
@@ -38,4 +39,4 @@ library
      , nicify-lib
      , ansi-terminal
      , vector
-    default-language: Haskell2010
+    default-language: GHC2021