scripts: Add a script to generate the list of apps to rebuild

This opens whatever apps has the module name [1] in its current frozen requirements. If the constraint of module name and version does not match, it outputs said application as being impacted.

On current master for that repository, this behaves adequately [2]

[1] application name transformed as pypi module name

[2]

$ ./scripts/list-apps-to-rebuild swh-loader-core 5.2.0
swh-loader-bzr
swh-loader-cvs
swh-loader-git
swh-loader-highpriority
swh-loader-mercurial
swh-loader-package
swh-loader-svn
$ ./scripts/list-apps-to-rebuild swh-loader-core 5.1.0
swh-loader-bzr
swh-loader-cvs
swh-loader-mercurial
$ grep swh.loader.core apps/swh-loader-bzr/requirements-frozen.txt
swh.loader.core==4.2.0
$ grep swh.loader.core apps/swh-loader-cvs/requirements-frozen.txt
swh.loader.core==5.0.0
$ grep swh.loader.core apps/swh-loader-mercurial/requirements-frozen.txt
swh.loader.core==4.2.0

Ref. sysadm-environment#4724

cc @teams/sysadmin