Overhaul access pattern [all tests ci]

[lsetiawan]

This PR overhauls the old attribute based access pattern in favor of path key access pattern for EchoData.

Resolves #708

[codecov-commenter]

Codecov Report

Merging #762 (182852a) into dev (0095f15) will decrease coverage by 0.15%.
The diff coverage is 94.36%.

@@            Coverage Diff             @@
##              dev     #762      +/-   ##
==========================================
- Coverage   82.33%   82.18%   -0.16%     
==========================================
  Files          46       48       +2     
  Lines        4240     4249       +9     
==========================================
+ Hits         3491     3492       +1     
- Misses        749      757       +8     

Flag	Coverage Δ
unittests	82.18% <94.36%> (-0.16%)	⬇️

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

Impacted Files	Coverage Δ
echopype/echodata/combine.py	90.32% <76.47%> (+0.40%)	⬆️
echopype/calibrate/api.py	81.63% <100.00%> (ø)
echopype/calibrate/calibrate_azfp.py	96.22% <100.00%> (ø)
echopype/calibrate/calibrate_ek.py	94.28% <100.00%> (ø)
echopype/calibrate/env_params.py	92.98% <100.00%> (ø)
echopype/convert/api.py	84.78% <100.00%> (ø)
echopype/echodata/echodata.py	80.87% <100.00%> (-2.90%)	⬇️
echopype/consolidate/api.py	90.90% <0.00%> (ø)
echopype/consolidate/__init__.py	100.00% <0.00%> (ø)

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

[leewujung]

Hey @lsetiawan : thanks for the PR! Sorry it took me forever to get to this.

The PR looks great, there's just this repeated block that handles whether beam is connected to echodata["Sonar/Beam_group1"] or echodata["Sonar/Beam_group2"] that I feel the if/else + try/except logic should be a little different. See what you think, it is possible that I misunderstood something.

[lsetiawan]

@leewujung This is now ready for your final review hopefully 😄

[leewujung]

Awesome, thanks! I think once it's merged there would be some conflicts popping up for #774. Since you have both on your mind, perhaps it won't be so bad!

[leewujung]

I like this!

[leewujung]

@b-reyes : the test_setitem and test_getitem are the type of unit tests I was thinking for the changes you made in #774. Just making a note here as it came to my mind while reviewing this. We can circle back to that and your ideas in our tests-hackday!

[leewujung]

@lsetiawan : I think this PR is ready to be merged! Just had a minor suggestion on a comment. It is nice to see how changing the getitem output to None makes the code so much cleaner to read.