cmake: allow to --debug-find=PackageName the specified package

Sometimes it's needed to debug only one package for find_package(), but if project is large, it becomes difficult to "grep" the all log (especially on some kinds of CI, there are input lag exists too). The feature to upgrade the option --debug-find to allow some library (possibly libraries' names delimited by comma??) only dumps into the build log, excluding the other find_package() libraries.