This change will vendor the new version of the exoscale-import
post-processor component, but remove all of its code from Packer. After
the v1.8.0 release this change should be removed entirely.
This vendor process is being used as a workaround for decoupling the
exoscale-import component without causing a breaking change in Packer.
Users of Exoscale are encouraged to leverage `packer init` for
installing the latest version of packer-plugin-exoscale.
Let's cache the scancodes and flush them at the end. Also make sure to
send only as many as the driver can send correctly. It's important here
to chunk the scancodes correctly, so that we don't accidentally split them
over successive calls to the driver
