Package Kit: Proper Installation for First Boot Packages

Do the final installation operations for all the packages in the
/system/packages directory when the OS is booted for the first time.

This will run their post-install scripts, create users, groups and generate
settings files (marked with a package version attribute). Previously we just
ran all the shell scripts found in the /system/boot/post-install directory
(don't do that as much now).

Fixes bug #14382

This patch has simpler code flow in CommitTransactionHandler::_ApplyChanges
Tested on 32 and 64 bit systems. Once it's official, need to remove the
open_ssh redundant post-install script that creates users etc. from HaikuPorts.
Now we can notice bugs like package version attributes on settings files aren't
fully working. :-)

Didn't remove special case for add_catalog_entry_attributes.sh since it
still does stuff that the build system doesn't do. Might be able to add
that script as part of the Haiku.hpkg. See change 3751 for removing it,
https://review.haiku-os.org/c/haiku/+/3751

Change-Id: I3807b78042fdb70e5a79eca2e2a45816ece0236f
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2342
Reviewed-by: Alexander G. M. Smith <agmsmith@ncf.ca>
Reviewed-by: Niels Sascha Reedijk <niels.reedijk@gmail.com>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>

package_daemon: queue post-install scripts to run after reboot

* Creates symlinks to the post-install scripts into the
administrative/queued-scripts directory.
* Upon reboot, post-install scripts in the queued-scripts
are run, and then the symlinks to the scripts removed.
* This solves the issue of post-install scripts not being
run when the package is installed/upgraded along with the
system packages, as experienced with the latest upgrade
to the bash package.

package daemon: Initial old packages state support

* VolumeState: Move locking to Volume.
* Package: Pull the file related functionality into new class
PackageFile. A Package refers to a PackageFile. A PackageFile can be
referenced by multiple Packages. PackageFiles are managed by the new
PackageFileManager.
* CommitTransactionHandler: Clone the passed volume state.
* Volume now manages two VolumeStates: A state reflecting the currently
active packages and the latest state (i.e. the one reflecting the
situation of the packages directory). Usually the two are the same,
unless an old state has been booted.
* The client interface hasn't been adjusted yet. Clients only see the
latest state.

Move Volume::CommitTransactionHandler to top level

Also move constant definitions to Constants.h/cpp.

package_daemon: queue post-install scripts to run after reboot

* Creates symlinks to the post-install scripts into the
administrative/queued-scripts directory.
* Upon reboot, post-install scripts in the queued-scripts
are run, and then the symlinks to the scripts removed.
* This solves the issue of post-install scripts not being
run when the package is installed/upgraded along with the
system packages, as experienced with the latest upgrade
to the bash package.

package daemon: Initial old packages state support

* VolumeState: Move locking to Volume.
* Package: Pull the file related functionality into new class
PackageFile. A Package refers to a PackageFile. A PackageFile can be
referenced by multiple Packages. PackageFiles are managed by the new
PackageFileManager.
* CommitTransactionHandler: Clone the passed volume state.
* Volume now manages two VolumeStates: A state reflecting the currently
active packages and the latest state (i.e. the one reflecting the
situation of the packages directory). Usually the two are the same,
unless an old state has been booted.
* The client interface hasn't been adjusted yet. Clients only see the
latest state.

Move Volume::CommitTransactionHandler to top level

Also move constant definitions to Constants.h/cpp.