Introduce `pyiron_mini`

[jan-janssen]

For users who just want to use pyiron as a workflow manager for any kind of python function or executable, pyiron_mini provides a minimal set of functions. You can import it as:

import pyiron_base.mini as pyiron_mini

Then you have access to:

• pyiron_mini.wrap_exe() to wrap external executables.
• pyiron_mini.wrap_py() to wrap python functions.
• pyiron_mini.cache_list() to list the currently cached tasks.
• pyiron_mini.cache_clear() to clear the cache.
• pyiron_mini.conda_create_env() to create new conda environments to execute tasks in.

If pyiron_mini is not short enough you can also import it as import pyiron_base.mini as pm in that case it is as short as the pr we commonly use to reference a Project object.