Renamed widgets subpackage to visualization and restructured modules within it

[jaladh-singhal]

Besides renaming, changed subpackage structure from:

widgets
├── __init__.py
├── line_info.py
├── plot_util.py
├── sdec_plot.py
├── shell_info.py
├── tests
│   ├── __init__.py
│   ├── test_line_info.py
│   └── test_shell_info.py
└── util.py

to:

visualization
├── __init__.py
├── plot_util.py
├── tools
│   ├── __init__.py
│   └── sdec_plot.py
└── widgets
    ├── __init__.py
    ├── line_info.py
    ├── shell_info.py
    ├── tests
    │   ├── __init__.py
    │   ├── test_line_info.py
    │   └── test_shell_info.py
    └── util.py

This way I've segregated tools and widgets similar to visualization docs:

key of difference	tools	widgets
contained modules	restructured tardisanalysis tools like SDEC plot	Jupyter widgets version of old GUI
can be generated through	both script and notebook	only notebook since they're "Jupyter" widgets
needs a running python kernel to render	no (check SDEC demo notebook, both matplotlib & plolty plots show up)	yes (check widgets demo notebook, widgets don't render instead GIF has to be used)

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This segregation won't affect how users will import modules (except the name has been changed from widgets to visualization) since all the important functions/classes are imported in top-level visualization directory's init file. Hence a user need not to know whether a functionality is tool or widget, they will simply import all functionality from visualization subpackage, e.g.:

• tool: from tardis.visualization import SDECPlotter
• widget: from tardis.visualization import LineInfoWidget

The changes in two notebooks in docs reflect the same.

Motivation and Context

Name visualization is more inclusive and understandable to wider audience, also docs refer this section same, hence renaming subpackage was essential. Restructure is essential for making it easier for developers to add new modules right way, without creating clutter and maintaining modularity in codebase.

How Has This Been Tested?

• Testing pipeline
• Reference Data Comparison following these instructions
• Other (please describe)

Screenshots (if appropriate):

Types of changes

• 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 not work as expected)
• None of the above (please describe)

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 built the documentation on my fork following these instructions
• I have assigned and requested two reviewers for this pull request

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Codecov Report

Merging #1462 (01ca927) into master (927c606) will decrease coverage by 1.13%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1462      +/-   ##
==========================================
- Coverage   71.13%   70.00%   -1.14%     
==========================================
  Files          67       67              
  Lines        5523     5314     -209     
==========================================
- Hits         3929     3720     -209     
  Misses       1594     1594              

Impacted Files	Coverage Δ
...dis/tardis/montecarlo/montecarlo_numba/r_packet.py	23.15% <0.00%> (-7.83%)	⬇️
.../tardis/montecarlo/montecarlo_numba/interaction.py	24.32% <0.00%> (-5.68%)	⬇️
.../montecarlo/montecarlo_numba/single_packet_loop.py	24.56% <0.00%> (-3.78%)	⬇️
...rdis/tardis/montecarlo/montecarlo_numba/vpacket.py	15.00% <0.00%> (-2.48%)	⬇️
tardis/tardis/plasma/properties/util/macro_atom.py	30.00% <0.00%> (-2.26%)	⬇️
...rdis/montecarlo/montecarlo_numba/tests/conftest.py	91.11% <0.00%> (-1.88%)	⬇️
tardis/tardis/plasma/properties/nlte.py	39.21% <0.00%> (-1.74%)	⬇️
...s/tardis/montecarlo/montecarlo_numba/macro_atom.py	43.75% <0.00%> (-1.71%)	⬇️
tardis/tardis/montecarlo/spectrum.py	70.00% <0.00%> (-1.70%)	⬇️
...is/tardis/plasma/properties/continuum_processes.py	41.66% <0.00%> (-1.58%)	⬇️
... and 39 more

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[ycamacho]

This is a good way to restructure the visualization tools. Good work!

[jamesgillanders]

looks good

[antreev-brar]

Loved the detailed description.