add stac search helper methods

[geospatial-jeff]

No description provided.

[codecov-io]

Codecov Report

Merging #70 (9db8869) into master (9818117) will decrease coverage by 1.68%.
The diff coverage is 79.71%.

@@            Coverage Diff             @@
##           master      #70      +/-   ##
==========================================
- Coverage   99.11%   97.42%   -1.69%     
==========================================
  Files          30       33       +3     
  Lines         677      778     +101     
==========================================
+ Hits          671      758      +87     
- Misses          6       20      +14     

Flag	Coverage Δ
unittests	97.42% <79.71%> (-1.69%)	⬇️

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

Impacted Files	Coverage Δ
stac_pydantic/shared.py	91.91% <61.90%> (-8.09%)	⬇️
stac_pydantic/item.py	94.36% <80.00%> (-1.29%)	⬇️
stac_pydantic/api/search.py	95.23% <87.50%> (-4.77%)	⬇️
stac_pydantic/api/extensions/fields.py	91.30% <89.47%> (-8.70%)	⬇️
stac_pydantic/scripts/cli.py	88.88% <0.00%> (-1.12%)	⬇️
stac_pydantic/catalog.py	100.00% <0.00%> (ø)
stac_pydantic/api/extensions/context.py	100.00% <0.00%> (ø)
stac_pydantic/api/utils/link_factory.py	100.00% <0.00%> (ø)
stac_pydantic/extensions/__init__.py	100.00% <0.00%> (ø)
... and 2 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b9f420e...9db8869. Read the comment docs.