antimerdian.fix_item creates latitude-band-spanning bbox instead of tight antimeridian-crossing bbox

[philvarner]

Describe the bug

In 0.4.7, calling antimeridan.fix_item with an antimeridian-crossing polygon or antimerdian-touching multipolygon and strategy SPLIT would create a multipolygon and a "tight" bbox that crossed the antimeridian (e.g., had positive sw longitude and negative ne longitude). In #426 , this behavior was changed so that instead of calculating the longitude from the polygons within the multipolygon, the bounds attribute of a shapely shape is used. However, shapely calculates the bounds as a latitude-band-spanning bbox, not accounting for the fact that a tighter bbox can be found by crossing the antimerdian.

To reproduce

This geometry in an Item when called with antimeridan.fix_item will create a latitude-spanning bbox instead of a tight one.

 "footprint" : {
    "type" : "MultiPolygon",
    "coordinates" : [ [ [ [ 180.0, 71.05915991175688 ], [ 179.9010750820252, 71.06541838862726 ], [ 179.33609176796372, 71.09933099986762 ], [ 178.94212273834066, 71.12173675373532 ], [ 178.8438129745677, 70.9444458447684 ], [ 178.752152818998, 70.76646311814699 ], [ 178.65805412647518, 70.58865453189631 ], [ 178.56519747139944, 70.41081414405018 ], [ 178.47354940789182, 70.23294268101853 ], [ 178.3830776723032, 70.0550408551604 ], [ 178.29375108586135, 69.87710927076108 ], [ 178.20553958576738, 69.69914858383564 ], [ 178.11841414688843, 69.52115944285417 ], [ 177.94089921353645, 69.16547224310027 ], [ 177.84841186280488, 68.98789251198602 ], [ 177.6811017579393, 68.63180788289334 ], [ 177.59856429364814, 68.45374564350413 ], [ 177.5170097254968, 68.27565414719149 ], [ 177.35557827100007, 67.91945640451053 ], [ 177.27786157853095, 67.74121946580148 ], [ 177.2008812187222, 67.5629645683486 ], [ 177.04801561874308, 67.20647273987551 ], [ 176.999842641033, 67.08652173541694 ], [ 177.33004216473563, 67.06599963683973 ], [ 177.80402381607067, 67.0350911283458 ], [ 178.2797509869322, 67.00256994873874 ], [ 178.75469524409255, 66.96859439018418 ], [ 179.22826647862672, 66.9332058638613 ], [ 179.69748316523564, 66.89664359586376 ], [ 180.0, 66.87210508518304 ], [ 180.0, 71.05915991175688 ] ] ], [ [ [ -180.0, 71.05915991175688 ], [ -180.0, 66.87210508518304 ], [ -179.8356900497663, 66.85877716089777 ], [ -179.3711345161936, 66.81960857957779 ], [ -178.90872065703624, 66.77913696435182 ], [ -178.44665752494657, 66.73720767705268 ], [ -177.98865515860075, 66.69416388262516 ], [ -177.52780114205189, 66.6493554890298 ], [ -177.07275963647132, 66.6036210941224 ], [ -176.60787845770125, 66.55536115330877 ], [ -176.1601824748328, 66.50739485114256 ], [ -175.70001915807038, 66.4565657047866 ], [ -175.2469931583778, 66.40499213010705 ], [ -174.7964900612594, 66.35218457280217 ], [ -174.34347993447946, 66.29754039236374 ], [ -173.93806864778026, 66.24724531349037 ], [ -173.84461372118676, 66.36429279141416 ], [ -173.71659543892704, 66.53996608675018 ], [ -173.56903550480715, 66.7133044234658 ], [ -173.42527581962764, 66.88723670581788 ], [ -173.13377948252224, 67.23496576919374 ], [ -172.9861602177385, 67.40878187666635 ], [ -172.83662520799953, 67.58248608985471 ], [ -172.68512898875264, 67.75607579888592 ], [ -172.53162554562746, 67.92954828162647 ], [ -172.3760685337871, 68.10290084143905 ], [ -172.2184100683418, 68.27613086321372 ], [ -172.05860098199193, 68.44923546830157 ], [ -171.89659058995878, 68.6222117159503 ], [ -171.73232652538707, 68.79505671303144 ], [ -171.5657549702618, 68.96776730324396 ], [ -171.39682036750511, 69.14034030642564 ], [ -171.2254655001628, 69.31277236817284 ], [ -171.0516311905371, 69.48506019171748 ], [ -170.87525658150514, 69.65720018398522 ], [ -170.6962788340423, 69.82918868566634 ], [ -170.51463300157428, 70.00102201028209 ], [ -170.33062092998924, 70.17235288521945 ], [ -170.8013714414895, 70.22969914468295 ], [ -171.32505679115005, 70.2915919758267 ], [ -171.85186730974112, 70.35195515326475 ], [ -172.3817527878377, 70.41077446610994 ], [ -172.9146602469648, 70.46803605371709 ], [ -173.45053416371871, 70.52372627412625 ], [ -173.98931653005684, 70.5778316447626 ], [ -174.53094682771086, 70.6303388535604 ], [ -175.07536190589843, 70.68123489897708 ], [ -175.62249600000058, 70.73050710549359 ], [ -176.17228091814727, 70.77814294613066 ], [ -176.72464582082006, 70.82413036939441 ], [ -177.2795175859301, 70.86845740126327 ], [ -177.83682058594974, 70.91111247989673 ], [ -178.39647668879172, 70.95208453426882 ], [ -178.96676234549457, 70.99192936610521 ], [ -179.53562414647374, 71.02978121124382 ], [ -180.0, 71.05915991175688 ] ] ] ]
  }

Expected behavior

antimeridian.fix_item creates a tight, antimeridian-crossing bbox.