Geopandas.GeoSeries: Implement proper index behavior for _row_wise_operations

[petern48]

After we get index support (#2036), revisit the align behavior for the row-wise operations, discussed in this PR originally #2038.

Specifically we should investigate the comments copilot made. The suggested fixes weren't right, but we may be missing something.

• Set the index properly. It seems to be a union.

geoseries = gpd.GeoSeries([Polygon([(0, 0), (1, 0), (1, 1)]), Polygon([(0, 0), (1, 0), (1, 1)]), Polygon([(0, 0), (1, 0), (1, 1)])], index=[1, 2, 3])
geoseries2 = gpd.GeoSeries([Polygon([(0, 0), (1, 0), (1, 1)]), Polygon([(0, 0), (1, 0), (1, 1)]), Polygon([(0, 0), (1, 0), (1, 1)])], index=[0, 1, 2])
res = geoseries.intersection(geoseries2, align=True)
print(res)
print(res.index)

0                              None
1    POLYGON ((0 0, 1 1, 1 0, 0 0))
2    POLYGON ((0 0, 1 1, 1 0, 0 0))
3                              None
dtype: geometry
Index([0, 1, 2, 3], dtype='int64')

• Investigate: Is it really an outer join really correct in all cases? Or could it be something more along the lines of a union of left and right?