Add installation and packaging targets

[jnagasawa]

GitLab: nagasaji

I completed the optional and bonus tasks.

How to Install:

docker build -t cpack-exercise .
docker run --rm -it --entrypoint /bin/bash -v "$(pwd):/mnt/cpack-exercise" cpack-exercise

lintian output:

root@8b249e6f7d48:/mnt/cpack-exercise# lintian ./cpackexample_0.1.0_arm64.deb 
running with root privileges is not recommended!
E: cpackexample: lacks-ldconfig-trigger usr/lib/libcpackexamplelib.so
E: cpackexample: no-changelog usr/share/doc/cpackexample/changelog.gz (native package)
E: cpackexample: no-copyright-file
W: cpackexample: extended-description-line-too-long line 1
W: cpackexample: maintscript-calls-ldconfig [postinst]
W: cpackexample: maintscript-calls-ldconfig [postrm]
W: cpackexample: no-manual-page [usr/bin/cpackexample]
W: cpackexample: package-name-doesnt-match-sonames libcpackexamplelib
W: cpackexample: shared-library-lacks-version usr/lib/libcpackexamplelib.so libcpackexamplelib.so