Add kexec debug log lines

[micahhausler]

Description

Add debug log lines for kexec action. Debugging

Why is this needed

When Kexec doesn't work, it'd be nice to know where in the process it breaks down.

How Has This Been Tested?

"Works on my machine" -Every pull request author

But really, I ran this in an effort to diagnose #57

INFO[0000] Loaded boot config: &grub.Config{Name:"'Debian GNU/Linux' ", Kernel:"/boot/vmlinuz-4.19.0-16-cloud-amd64", Initramfs:"/boot/initrd.img-4.19.0-16-cloud-amd64", KernelArgs:"root=UUID=af5f8c82-a495-40e0-b3e6-f361abeec5a4 ro nosplash text biosdevname=0 net.ifnames=0 console=tty0 console=ttyS0,115200 earlyprintk=ttyS0,115200 consoleblank=0 systemd.show_status=true", Multiboot:"", MultibootArgs:"", Modules:[]string(nil)} 
INFO[0000] Running Kexec: kernel: /mountAction/boot/vmlinuz-4.19.0-16-cloud-amd64, initrd: /mountAction/boot/initrd.img-4.19.0-16-cloud-amd64, cmdLine: root=UUID=af5f8c82-a495-40e0-b3e6-f361abeec5a4 ro nosplash text biosdevname=0 net.ifnames=0 console=tty0 console=ttyS0,115200 earlyprintk=ttyS0,115200 consoleblank=0 systemd.show_status=true 
INFO[0000] Rebooting system     

How are existing users impacted? What migration steps/scripts do we need?

Existing users don't have much visibility when kexec doesn't work properly

Checklist:

I have:

• [x] updated the documentation and/or roadmap (if required) N/A
• [x] added unit or e2e tests N/A
• [x] provided instructions on how to upgrade N/A