cleanup: reorganized messenger assets and removed obsolete unused scripts

fix: GENERIC handoff in auto.cpanel.pl to exec auto.pl

refactor: consolidating CWP, Vesta and DA auto-upgrade scripts into auto.pl

refactor: creating one unified auto-upgrade script

refactor: splitting cPanel auto update logic in separate script

refactor(conf): group panel config files into subdirectories

refactor(installer): move installer payload files under lib

refactor(installer): generate csf.help during install and move manpage under the lib folder

refactor(installer): move shared UI assets to panels/csf and drop redundant conf/ui/images

fix: update installer asset/doc paths after UI/docs layout changes reported in #8

Merge remote-tracking branch 'origin/main'

Added GitHub issue template

Merge pull request #7 from zeroth-blip/chore/remove-module-installed-tiny

chore: remove unused Module::Installed::Tiny vendored module

test: accept normalized empty file arg in URLGet fallback path