feat(agent_install): only install required packages [SMAGENT-6558]

[iurly]

rework the role so to only install the packages required by the
selected driver (and therefore, the respective dependencies).
Also, remove packages which are no longer required by the
selected driver type.

Notice we need to craft a list augmented with the selected
version, if one is present.

Most of the selection logic (namely, based on the version)
resides in the 'agent' filter which is probably far from
ideal but gets the job done.

Side changes to make CI pass on this PR:

• DO NOT delete environment file in case of kmod (otherwise agent 13.1.0 will fail)
• DO NOT RUN tests on Ubuntu 18.04 (due older systemd not accepting non-absolute path for kill -- otherwise agent 13.1.0 will fail)
• execute local forwarder test on EC2 instead of container (due to systemd unit)

[aroberts87]

At least to me, keying the package map off of the driver type makes things a bit more straight forward. As an example:

package_map = {
  "universal_ebpf": ["draios-agent-slim"],
  "legacy_ebpf": ["draios-agent-slim", "draios-agent-legacy-ebpf"],
  "kmod": ["draios-agent", "draios-agent-slim", "draios'agent-kmodule"]
}
...
if older:
  return ["draios-agent"]
return package_map[to_agent_driver_type(data)]

In this way we don't have to manually "flip the switch" for packages to install for a given driver and also there is a clear mapping between driver type and package.

The to_agent_install_packages() and to_agent_uninstall_packages() methods can be simplified to something like this as well:

to_agent_uninstall_packages()

# hacky global. could make better.
AGENT_PACKAGES = ["draios-agent", "draios-agent-legacy-ebpf", "draios-agent-slim", "draios-agent-kmodule"]
...
def to_agent_uninstall_packages(data):
  return [p for p in AGENT_PACKAGES if p not in to_agent_packages(data)]

to_agent_install_packages(data):

def to_agent_install_packages(data):
  return to_agent_packages(data)