Improve installing Solus as dual boot with Windows system using a separate drive

[TraceyC77]

Other distros make installing along with Windows much easier Attempting to install Solus alongside Windows did not result in Solus being added to the boot menu, Solus cannot boot

Use case: UEFI system Drive with Windows installation Separate drive to be used with Solus installation Manual partitioning (/ and /home at least)

Current result: Existing EFI partition was not updated to boot Solus along with Windows (EFI partition was resized to 1G)

Desired result: Solus installer updates the UEFI boot entries on the existing EFI partition to add Solus