pfSense

Fix #6460 Interface mismatch apply changes button

Rework pkg_mgr_install.php:

- Stop using id parameter for additional packages, keep using it only
for firmware upgrades
- Created to control variables $completed and $confirmed to check all
the stages and make it easy to understand what is happening
- Stop using $pkgid and use $pkgname instead...

Fix variable name s/POST/_POST/ and also parameter name s/complete/completed/

Fix indent

Improve readability

Improve readability

Simplify mode parameter validation

Remove redundant check since pkgcancel is never set

Validate mode parameter and use sanitized variable on other places

Fix save and reset buttons on status_lb_pool.php. Ticket #6254