Rename 'lasloader' package and any associated references in repo

Related to #32 (closed)

Now the repo has been renamed to 'data loader' it would make sense to rename the package from 'lasloader' to something else.

There are lots of other references to specifically LAS throughout the repo ('lasloader' and 'lascli' being the most obvious) - these would also all need to be changed to remain consistent.

Things to do:

• Rename source code folders (packages)
• Rename lascli filename.
• Update the build and publish pipeline
• Fix comments in code.
• Update documentation.
• Test it all still works.