Remove symlink of backend data files

[rlizzo]

Motivation and Context

Why is this change required? What problem does it solve?:

Remove symlink of data files between stage, store, and remote holding directories. This is both a confusing practice, and incompatible with privileges on some platforms (google colab connected to a mounted drive).

If it fixes an open issue, please link to the issue here:

• closes Symbolic Link Priveliges #140

Description

Describe your changes in detail:

replace symlink data files with touched files in same staging, remote and store locations.

At time of writing, am not 100% certain this won't break backwards compatibility with 0.4 symlinks. It shouldn't (since general structure and naming conventions are honored) but need tests to prove it.

Types of changes

What types of changes does your code introduce? Put an x in all the boxes that apply:

• Documentation update
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Is this PR ready for review, or a work in progress?

• Ready for review
• Work in progress

How Has This Been Tested?

Put an x in the boxes that apply:

• Current tests cover modifications made
• New tests have been added to the test suite
• Modifications were made to existing tests to support these changes
• Tests may be needed, but they are not included when the PR was proposed
• I don't know. Help!

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have signed (or will sign when prompted) the tensorwork CLA.
• I have added tests to cover my changes.
• All new and existing tests passed.

[codecov]

Codecov Report

Merging #171 into master will decrease coverage by 0.05%.
The diff coverage is 94.48%.

@@            Coverage Diff             @@
##           master     #171      +/-   ##
==========================================
- Coverage   95.28%   95.23%   -0.05%     
==========================================
  Files          66       66              
  Lines       11878    11862      -16     
  Branches     1029     1011      -18     
==========================================
- Hits        11317    11296      -21     
+ Misses        374      370       -4     
- Partials      187      196       +9

Impacted Files	Coverage Δ
src/hangar/dataloaders/tfloader.py	100% <100%> (ø)	⬆️
src/hangar/dataloaders/torchloader.py	100% <100%> (ø)	⬆️
src/hangar/__init__.py	100% <100%> (ø)	⬆️
tests/test_dataloaders.py	100% <100%> (+1.12%)	⬆️
tests/test_cli.py	99.59% <100%> (+0.01%)	⬆️
src/hangar/utils.py	95.49% <100%> (+2.41%)	⬆️
src/hangar/backends/hdf5_01.py	88.66% <81.25%> (-1.49%)	⬇️
src/hangar/backends/hdf5_00.py	91.67% <84.38%> (-1.32%)	⬇️
src/hangar/backends/numpy_10.py	90.3% <86.67%> (-2.61%)	⬇️
src/hangar/records/commiting.py	91.06% <86.67%> (+1.14%)	⬆️
... and 5 more

[rlizzo]

@hhsecond please review.

[hhsecond]

Other than minor changes with Path, looks good