Add spec file for nnf-datamovement packages

[behlendorf]

Provide a basic spec file for building both library and development packages. This commit does not add a build target to generate the packages but one could certainly be wired up with a bit of work to pass through the version information.

Example rpmbuild using release tarball:

sudo dnf install rpmdevtools
rpmdev-setuptree

export VERSION=0.1.19
curl -L -o ${HOME}/rpmbuild/SOURCES/nnf-dm-${VERSION}.tar.gz \
  https://github.com/NearNodeFlash/nnf-dm/archive/refs/tags/v${VERSION}.tar.gz

sudo yum-builddep ./nnf-dm.spec
rpmbuild -ba nnf-dm.spec

A couple additional notes:

1. I've left this as a draft since a bit more work is required if there's interest in wiring it up as a build target.
2. When building on a TOSS 4 distribution you'll see that an epoch is set. This is only important for our systems where packages with a higher version number were built, before the current versioning scheme was established. The epoch ensure we ignore those older packages.
3. There a little slight of hand in the spec file where tester-dynamic binary is installed as nnf-dm.