Extra metadata flags not extracted for query from LAS Zip (LAZ) file

[gwlucastrig]

When the Tinfour Viewer reads a LAZ-formatted file (compressed LAS), it does not report GPS time, return status, and other elements that are not normally loaded from the file when the vertices are first read. This feature works for ordinary LAS files, but does not work for LAZ files because the tinfour-viewer code cannot randomly-access a zipped file.

Until this shortcoming is fixed, the only way a user can inspect GPS time is by unzipping the LAZ file (using laszip utility) and converting it to a standard LAS file.