ENH: Add support for transforming bounds at the poles

[snowman2]

Script:

from pyproj import CRS, Transformer
crs = CRS("EPSG:32661")
tr = Transformer.from_crs(crs, 4326, always_xy=True)
bounds = tr.transform_bounds(*crs.area_of_use.bounds, direction="INVERSE")
print(crs)
print(crs.area_of_use.bounds)
print(bounds)
print(tr.transform_bounds(*bounds))
crs = CRS("EPSG:32761")
tr = Transformer.from_crs(crs, 4326, always_xy=True)
bounds = tr.transform_bounds(*crs.area_of_use.bounds, direction="INVERSE")
print(crs)
print(crs.area_of_use.bounds)
print(bounds)
print(tr.transform_bounds(*bounds))

Current version (3.2.1)

EPSG:32661
(-180.0, 60.0, 180.0, 90.0)
(-1371213.7625429356, -1405880.71737131, 5371213.762542935, 5405880.71737131)
(-180.0, 48.65640565307887, 174.85815802748752, 60.292277663390834)
EPSG:32761
(-180.0, -90.0, 180.0, -60.0)
(-1371213.7625429356, -1405880.71737131, 5371213.762542935, 5405880.71737131)
(-174.8581580274875, -60.292277663390834, 180.0, -48.65640565307887)

With this PR:

EPSG:32661
(-180.0, 60.0, 180.0, 90.0)
(-1371213.7625429356, -1405880.71737131, 5371213.762542935, 5405880.71737131)
(-180.0, 48.65640565307887, 180.0, 90.0)
EPSG:32761
(-180.0, -90.0, 180.0, -60.0)
(-1371213.7625429356, -1405880.71737131, 5371213.762542935, 5405880.71737131)
(-180.0, -90.0, 180.0, -48.65640565307887)

[codecov]

Codecov Report

Merging #962 (1be2e27) into master (c714f59) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #962   +/-   ##
=======================================
  Coverage   96.23%   96.23%           
=======================================
  Files          20       20           
  Lines        1753     1753           
=======================================
  Hits         1687     1687           
  Misses         66       66           

Impacted Files	Coverage Δ
pyproj/transformer.py	94.68% <ø> (ø)

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