Fix the install of the single header amalgate in catch2.
The public API for catch < 2.3.0 was "#include <catch.hpp>".
For 2.3.0+ it is "#include <catch2/catch.hpp>"
- 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
* Catch2: 2.3.0+
Add the latest two releases of Catch2.
In 2.3.0+, the include changed to a future-proof
`<catch2/catch.hpp>` path which dependent projects will break upon.
* openPMD-api: Catch2 2.3.0+
openPMD-api just updated to use the new, future-proof Catch2
headers `<catch2/catch.hpp>`.
Add a proper install variant for Catch(2).
This allows to use Catch2 downstram with `pkg-config` and
CMake's `find_package` commands via standard environment hints.
* Adds catch, cppunit, spdlog, tinyxml(1 and 2), google benchmark
Tinyxml comes in two flavors, 1 and 2. Each comes in several
versions... So they cannot be easily united into a single package.
* Use CMakePackage and friends, add copyright
Also eleminate debug/release variants, since it no longuer fits in the
CMakePackage format.
* Remove unnecessary url
* spdlog now has tagged releases
* Remove unnecessary url argument
* Fewer quotes in cmake args, because magic
* Incorrect base class for tinyxml
