Redo writer in C++

[paleolimbot]

Fixes #56.

[codecov-commenter]

Codecov Report

Merging #74 (873d27d) into master (4b5f90d) will decrease coverage by 0.92%.
The diff coverage is 90.00%.

@@            Coverage Diff             @@
##           master      #74      +/-   ##
==========================================
- Coverage   97.13%   96.21%   -0.93%     
==========================================
  Files          33       34       +1     
  Lines        3005     3093      +88     
==========================================
+ Hits         2919     2976      +57     
- Misses         86      117      +31     

Impacted Files	Coverage Δ
R/compat-sf.R	100.00% <ø> (ø)
R/compat-wk.R	100.00% <ø> (ø)
src/geoarrow-imports.h	6.25% <6.25%> (ø)
R/geos-geometry.R	98.78% <66.66%> (-1.22%)	⬇️
src/geos-writer.cpp	94.68% <94.68%> (ø)

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