feat: add entrypoint for cape and cin

[VeraChristina]

Description

Adds an entrypoint to compute CAPE/CIN on AIFS outputs. Based on this PR in earthkit-meteo:ecmwf/earthkit-meteo#163

Open questions:

• How do we handle output types of cape/cin? The current implementation is based on the assumption that we want to output mucape/mucin, mlcape50/mlcin50, and mlcape100/mucape100. Do we want to make this configurable? How do we handle paramIds?
• update to changes in earthkit-meteo API for cape/cin
• Need to test if processing the whole globe at once works for higher spatial resolutions.

Out of scope:

• IFS set-up (since cape/cin is an output of the IFS)
• maxCAPE/maxCIN (as it requires hourly resolution)

Contributor Declaration

By opening this pull request, I affirm the following:

• All authors agree to the Contributor License Agreement.
• The code follows the project's coding standards.
• I have performed self-review and added comments where needed.
• I have added or updated tests to verify that my changes are effective and functional.
• I have run all existing tests and confirmed they pass.