feat: add wrapper functions to read and interpolate constants

[tsutterley]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 76.48810% with 79 lines in your changes missing coverage. Please review.

Project coverage is 71.86%. Comparing base (d97482b) to head (28573fc).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
pyTMD/io/model.py	62.87%	40 Missing and 9 partials ⚠️
pyTMD/predict.py	69.62%	23 Missing and 1 partial ⚠️
pyTMD/io/constituents.py	28.57%	5 Missing ⚠️
test/test_equilibrium_tide.py	98.21%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #349      +/-   ##
==========================================
+ Coverage   71.59%   71.86%   +0.27%     
==========================================
  Files          39       41       +2     
  Lines       10495    10764     +269     
  Branches     1407     1447      +40     
==========================================
+ Hits         7514     7736     +222     
- Misses       2517     2554      +37     
- Partials      464      474      +10     

Flag	Coverage Δ
unittests	71.86% <76.48%> (+0.27%)	⬆️

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

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.