Compile set of real-world LAS 3 files

[kinverarity1]

Is your feature request related to a problem? Please describe. We don't have a diverse set of real-world LAS 3 files to develop and test against (refer to #5)

Describe the solution you'd like Add a small (6-12) number of diverse LAS 3 files (freely available i.e. compatible with the MIT license) to the tests/examples/3.0 folder.

Describe alternatives you've considered N/A

Additional context N/A