Answer the extended WKB of a geometry as the buffer it is

[estebanzimanyi]

The catalog states size as the parameter MEOS writes the length of
geo_as_ewkb's buffer into, so the method reads it: AsEWKB(string endian)
answers a byte[] exactly as long as the data, joining the twenty-eight other
buffers the layer already folds that way. The length is the whole of it — an
extended WKB buffer carries no terminator and no length of its own, so a caller
holding the pointer without it has no way to say where the geometry ends.

The layer emits 1353 methods over 115 classes with 7 deferred. Its own test
reads the hex form of the same geometry as an independent statement of the same
length: AsHexewkb answers a string of exactly twice as many characters, and
hex-encoding the buffer reproduces it character for character, so a buffer of
the wrong length fails on the count before it fails on the content. The second
test round-trips the bytes back through FromEWKB to the value they came from.