mkosi: Enable History= option

mkosi: Enable History= option

This option makes mkosi "remember" all the CLI options specified on
the command line when building an image. This means they don't need
to be specified again when booting the image afterwards or doing any
other operation on the image with "mkosi xxx".

As an example of how this is useful, currently, when running "mkosi
-d opensuse -f" to build an opensuse image and then running "mkosi
sandbox -- meson test -C build TEST-86-MULTI-UKI-PROFILE", running
the test will try to add virtiofs mounts of the fedora~rawhide build
directory on my machine instead of the opensuse one. With the History=
option enabled, it will use the opensuse tumbleweed directory as expected.

We stop setting --extra-search-path and --output-dir in the integration test
wrapper as these are settings that are "remembered" by enabling the History=
option.