Implements #6841 Add Bootstrap icons and make module icons configurable in module.conf.php

interface/web/admin/lib/module.conf.php

interface/web/client/lib/module.conf.php

interface/web/dashboard/dashlets/modules.php

interface/web/dashboard/dashlets/templates/modules.htm

interface/web/dashboard/lib/module.conf.php

interface/web/dns/lib/module.conf.php

interface/web/help/lib/module.conf.php

interface/web/login/lib/module.conf.php

interface/web/mail/lib/module.conf.php

interface/web/mailuser/lib/module.conf.php

interface/web/monitor/lib/module.conf.php

interface/web/nav.php

interface/web/sites/lib/module.conf.php

...themes/default/assets/stylesheets/bootstrap-icons.min.css

...mes/default/assets/stylesheets/fonts/bootstrap-icons.woff

...es/default/assets/stylesheets/fonts/bootstrap-icons.woff2

...rface/web/themes/default/assets/stylesheets/ispconfig.css

interface/web/themes/default/templates/main.tpl.htm

interface/web/themes/default/templates/topnav.tpl.htm

interface/web/tools/lib/module.conf.php