ogma-core: Remove dependency on IfElse. Refs #150.

[ivanperez-keera]

Replace uses of definitions from IfElse with other functions from base, as prescribed in the solution proposed for #150.

[ivanperez-keera]

Change Manager: Verified that:

• Solution is implemented:
  • The code proposed compiles passes the tests. Details:
    • Build logs:
      • https://github.com/nasa/ogma/actions/runs/10980588665/job/30486565255
      • https://github.com/nasa/ogma/actions/runs/10980588664/job/30486565078
    • Build log archives:
      • logs_28691603236.zip
      • logs_28691603237.zip
  • The solution proposed fixes the issues described.
    The following docker file checks that no cabal package depends on IfElse, in which case it prints the message success:

    FROM ubuntu:focal
    
    RUN apt-get update
    
    RUN apt-get install --yes git
    
    SHELL ["/bin/bash", "-c"]
    CMD git clone $REPO \
        && cd $NAME \
        && git checkout $COMMIT \
        && ! grep -niHre 'IfElse' --include='*.cabal' ogma** \
        && echo "Success"

    Command:

    docker run -e "REPO=https://github.com/ivanperez-keera/ogma" -e "NAME=ogma" -e PAT="ogma-" -e "COMMIT=0db6542adbeeba654f4d011126a30a6adeeadb81" -it ogma-verify-150
    

• Implementation is documented. Details:
  No need for updates to documentation.
• Change history is clear.
• Commit messages are clear.
• Changelogs are updated.
• Examples are updated. Details:
  No examples affected.
• Required version bumps are evaluated. Details:
  No update needed; the improvement reduces dependencies.