#11528 updated Stage to always store a Package's source in a fixed
directory accessible via `Stage.source_path` This left behind a
number of packages which were expecting to access the source code
via `Stage.path`. This Updates those packages to use
`Stage.source_path` instead.
This also updates the name of the fixed directory: The original name
of the fixed directory was "src", so if an expanded archive created a
"src" directory, then users inspecting the directory structure could
see paths like "src/src" (which wasn't wrong but could be confusing).
Therefore this also updates the name of the fixed directory to
"spack-src".
- remove the old LGPL license headers from all files in Spack
- add SPDX headers to all files
- core and most packages are (Apache-2.0 OR MIT)
- a very small number of remaining packages are LGPL-2.1-only
