Use `linux_release` in names associated with building or testing
release-style binaries. Add a `.linux_package` helper to adjust
the release binary build behavior for package-specific jobs.
Base them on the existing `x86_64` specs. Update the centos
base image from centos 6 to centos 7 to get aarch64 support.
The resulting binaries require GLIBC 2.17.
Fixes: #17923
The spec added by commit facc240a45 (Utilities/Release: Add docker specs
to build and test Linux binaries, 2019-08-23) generates only the TGZ
package, but the old `Utilities/Release/linux64_release.cmake` script
also generated a STGZ package.
