In order to support iso creation on multiple arches with the templates
we need to be able to select different packages based on arch.
lorax-composer uses the arch-specific Lorax templates in order to
generate the output iso so this patch:
1. Creates a new template and type to parse it, live-install.tmpl
which contains only installpkg commands and #if clauses for arch
2. Removes bootloader related packages from the live-iso.ks
3. Remove dracut-config-rescue exclusion because it can cause problems
with some blueprints.
4. Switch logo requirement to system-logos which is satisfied by
generic-logos or fedora-logos. This prevents conflicts when a blueprint
installs fedora-release-workstation.
So in the future, if x86.tmpl, etc. need a new package to support
creating the iso it should be added to the correct section in
./share/live/live-install.tmpl
Resolves: rhbz#1673744
