[0.6.0a0] Add the ZnFlow package

[PythonFZ]

This PR introduces the ZnFlow package for the fundamental handling of Node connections.
Many parts of ZnTrack had to be changed internally but the general API remains.

TODOs

• add ZnFlow package
• add $nwd$
• fix lazy loading
• fix jupyter support
• add legacy tests back
• test if zn.outs or zn.metrics are not set in the run method.
• test zntrack.Project
• znflow getitem support
• rename get_affected_files to get_files
• add get_deps_if_node utils
• solve issue if a Node is being loaded in between two project.run calls.
• do not allow outs to be set in the __init__
• eager does not work with meta.Text
• add operating directory
• rename from_rev(origin=) to from_rev(remote=) to be compliant with git remote add
• fix issue if two experiments change parameters of different nodes
• move graph to project.graph
• have with Project(run=True, save=True) to avoid a closing project.run()
• add warning, if force is required? Only write zntrack / params.yaml if a Node is being changed? Do not default to --force.
• automatically name a Node. e.g. if a Node occurs multiple times, name it WriteOuts and then WriteOuts_1, ... ? This should be a keyword option.

[codecov]

Codecov Report

Merging #516 (3e94439) into main (770eed4) will decrease coverage by 6.70%.
The diff coverage is 90.55%.

@@            Coverage Diff             @@
##             main     #516      +/-   ##
==========================================
- Coverage   96.63%   89.94%   -6.70%     
==========================================
  Files          34       19      -15     
  Lines        1663     1193     -470     
  Branches      601      417     -184     
==========================================
- Hits         1607     1073     -534     
- Misses         56      119      +63     
- Partials        0        1       +1     

Flag	Coverage Δ
fulltest	88.01% <88.63%> (-7.96%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
zntrack/core/__init__.py	100.00% <ø> (ø)
zntrack/notebooks/jupyter.py	62.79% <ø> (ø)
zntrack/cli/__init__.py	87.80% <70.58%> (-8.97%)	⬇️
zntrack/project/zntrack_project.py	79.48% <78.76%> (-20.52%)	⬇️
zntrack/utils/node_wd.py	79.31% <79.31%> (ø)
zntrack/utils/__init__.py	84.44% <84.09%> (-15.56%)	⬇️
zntrack/fields/dvc/__init__.py	84.74% <84.74%> (ø)
zntrack/fields/field.py	91.52% <91.52%> (ø)
zntrack/core/nodify.py	95.33% <92.00%> (ø)
zntrack/fields/meta/__init__.py	92.00% <92.00%> (ø)
... and 6 more

... and 2 files with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more