Add pacman (alpm) parser support (#943)

Co-authored-by: Christopher Phillips <christopher.phillips@anchore.com>

test/integration/test-fixtures/image-pkg-coverage/pkgs/var/lib/pacman/local/ALPM_DB_VERSION

@@ -0,0 +1 @@
+9

test/integration/test-fixtures/image-pkg-coverage/pkgs/var/lib/pacman/local/pacman-6.0.1-5/desc

@@ -0,0 +1,57 @@
+%NAME%
+pacman
+
+%VERSION%
+6.0.1-5
+
+%BASE%
+pacman
+
+%DESC%
+A library-based package manager with dependency support
+
+%URL%
+https://www.archlinux.org/pacman/
+
+%ARCH%
+x86_64
+
+%BUILDDATE%
+1652116331
+
+%INSTALLDATE%
+1654074247
+
+%PACKAGER%
+Morten Linderud <foxboron@archlinux.org>
+
+%SIZE%
+4925474
+
+%REASON%
+1
+
+%GROUPS%
+base-devel
+
+%LICENSE%
+GPL
+
+%VALIDATION%
+pgp
+
+%DEPENDS%
+bash
+glibc
+libarchive
+curl
+gpgme
+pacman-mirrorlist
+archlinux-keyring
+
+%OPTDEPENDS%
+perl-locale-gettext: translation support in makepkg-template
+
+%PROVIDES%
+libalpm.so=13-64
+

test/integration/test-fixtures/image-pkg-coverage/pkgs/var/lib/pacman/local/pacman-6.0.1-5/files

@@ -0,0 +1,30 @@
+%FILES%
+etc/
+etc/makepkg.conf
+etc/pacman.conf
+usr/
+usr/bin/
+usr/bin/makepkg
+usr/bin/makepkg-template
+usr/bin/pacman
+usr/bin/pacman-conf
+usr/bin/pacman-db-upgrade
+usr/bin/pacman-key
+usr/bin/repo-add
+usr/bin/repo-elephant
+usr/bin/repo-remove
+usr/bin/testpkg
+usr/bin/vercmp
+usr/include/
+usr/include/alpm.h
+usr/include/alpm_list.h
+usr/lib/
+usr/lib/libalpm.so
+usr/lib/libalpm.so.13
+usr/lib/libalpm.so.13.0.1
+usr/lib/pkgconfig/
+usr/lib/pkgconfig/libalpm.pc
+
+%BACKUP%
+etc/pacman.conf	de541390e52468165b96511c4665bff4
+etc/makepkg.conf	79fce043df7dfc676ae5ecb903762d8b