move package data

[emanuel-schmid]

Changes proposed in this PR:

• Move data directory into the climada package directory in order to better isolate the climada package and avoid environment naming conflicts
• Analogous to PR climda-petals: #90

PR Author Checklist

• Read the Contribution Guide
• Correct target branch selected (if unsure, select develop)
• Descriptive pull request title added
• Source branch up-to-date with target branch
• Documentation updated
• Tests updated
• Tests passing
• No new linter issues
• Changelog updated

PR Reviewer Checklist

• Read the Contribution Guide
• CLIMADA Reviewer Checklist passed
• Tests passing
• No new linter issues

[peanutfun]

Looks great! All files are moved, the new directory is installed correctly with pip install, and importing Climada afterwards works. I searched for instances in the scripts and docs where the path might not have been updated but I found none.