Add CoordinateSequenceFilter to geom.js

[willcohen]

I'm working on making geo cross-compatible with Clojurescript in addition to Clojure, which means integrating JSTS alongside JTS, and ran into the same issue as #382.

geo performs all of its reprojection/transformation by implementing CoordinateSequenceFilter in JTS, and JTS Javadocs seem to suggest that this is the preferred method for doing that kind of transformation.

By creating a function that that implements the five methods of CoordinateSequenceFilter (and correctly returns the class to be able to satisfy hasInterface, assuming it's exportable from geom.js), transformations of all geometries seem to be working correctly using the same process here as in JTS.

@bjornharrtell

[codecov]

Codecov Report

Merging #402 into master will not change coverage.
The diff coverage is n/a.

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  Files         279      279           
  Lines       14245    14245           
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  Hits         8920     8920           
  Misses       5325     5325           

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[bjornharrtell]

That's a funky use of JSTS. :) I would like to support your use case and I'm fine with the change in this PR but I'm not fully understanding if you are also affected what was observed in #382 about empty interfaces_ which is a bit harder to fix?

[willcohen]

No -- in this case, in the new object that implements the filter interface, hasInterface seems fine with me just returning for interfaces_ a new single item array with[jsts.geom.CoordinateSequenceFilter] as its contents, and the application of the filter proceeds successfully from there.

Separately, thanks for all of your work on this library (and jts2geojson, which we've also been using for quite some time!)

[bjornharrtell]

Thanks for the kind words, I'll merge this now and hopefully get a new release out in a not too far future.