This is scylla-jmx part of https://github.com/scylladb/scylla/pull/5530
After we stopped replacing /usr/lib/scylla with symlink,
creating symlink on /opt/scylladb/scripts/jmx become meaningless,
so we can drop it now.
We able to introduce new symlink on /usr/lib/scylla, but it likely no user
directly invoke scripts under /usr/lib/scylla/jmx, so we don't have to
do that.
(cherry picked from commit 4c8660d41a)
Since systemd unit can override parameters using drop-in unit, we don't need
mustache template for them.
Also, drop --disttype option on install.sh since it does not required anymore,
introduce --sysconfdir instead for non-redhat distributions.
Move package build script from .rpm/.deb to single script, install.sh.
We need this to support nonroot mode, and also to keep package build script
consistent between .rpm/.deb.
