Added:
get_binary_path: Checks binary_directory for the wanted binary, if
if its not there, it will use which to find a
system one. returns the full path
install_if_needed: will install a binary only if it is not present.
Changes:
- Busybox is now deployed to non-rooted devices
- is_installed has now been removed as the new functions supersede it
- binaries will now always be installed to `binaries_directory` and
not system folders.
- updated workloads to use these new functions
- rt-app and sysbench might still need work
