CMake 3.27 deprecates compatibility with CMake < 3.5. Update tests that
do not cover older interfaces to avoid the deprecation warning.
Follow the pattern from:
* commit 7b07ccdd2b (Tests/*Only: Update cmake_minimum_required versions,
2020-06-15, v3.19.0-rc1~629^2~1)
* commit 72e7c45e98 (Tests: Bump CMake minimum required in tests to 2.8.12,
2020-12-22, v3.20.0-rc1~224^2)
* commit f6b4db365a (Tests: bump cmake_minimum_required version to 2.8.12,
2021-04-04, v3.21.0-rc1~372^2)
Also remove explicit `cmake_policy` settings made redundant by the
version.
add_jar() currently requires (undocumented) that resources be supplied
as relative paths. The resources *may* then end up in a path which does
not reflect the original path particularly when performing out-of-source
builds. This change adds a RESOURCE (and NAMESPACE) parameter and a
function to add the names resources into the named namespace within the
jar- and thus address both of these problems.
Fixes: #22101
