Unicode: make ucd2haskell build-able again (related #24789)

The main aim for these changes is to make ucd2haskell build-able again.

We scheduled to remove it completely to keep dependencies only on GHC repositories family but may be at will be implemented at another turn.

If you use ghc.nix and meet issue at MacOS during the build:

Building library for streamly-0.10.1......
ld: framework not found Cocoa
clang-16: error: linker command failed with exit code 1 (use -v to see invocation)
`cc' failed in phase `Linker'. (Exit code: 1)

Try the following:

1. Add darwin.apple_sdk.frameworks.Cocoa to ghc.nix.
2. Confirm by this trick (clang -Xlinker -v) that new environment has added Cocoa.