Adding the LasZipAppender support to the las-rs

[mkondratyev85]

Is it possible to add the functionality for appending point to the already existing laz file to the wonderful las-rs library?

The recent update in laz-rs crate adds the LasZipAppender and now it should be possible to append points to the already compressed file. My limited knowledge of rust makes it hard for me to actually use it (see laz-rs/laz-rs#50). Is it possible to add this functionality to the `las-rs' crate so it would be easier to actually add points?