Description

closes #1025

This PR adds RAI segment iterators to multilinestring_range and multipolygon_range.

Caveats: this iterator currently will fail if the range contains empty geometries (such as an empty linestring or an empty polygon).

Usage example:

multilinestring_range:
geometry: {0, 1, 2}
part: {0, 3, 6}
coordinates: {{0, 0}, {1, 1}, {2, 2}, {10, 10}, {11, 11}, {12, 12}}

range.segment_begin()[0] == {0, 0}, {1, 1}
range.segment_begin()[1] == {1, 1}, {2, 2}
range.segment_begin()[2] == {10, 10}, {11, 11}
range.segment_begin()[3] == {11, 11}, {12, 12}

range.num_segments() == 4

This PR also adds a few helper methods that will be used in pairwise_linestring_polygon_distance API. All of them are tested. Contributes to #991

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.