fix: use effectiveAppearance to check dark mode on mojave and above (#18666)
fix: use effectiveAppearance to check dark mode on mojave and above (#18666)

* fix: use effectiveAppearance to check dark mode on mojave and above

* chore: add forward declarations for dark appearance

gerhardberger/electron,bpasero/electron,bpasero/electron,electron/electron,bpasero/electron,the-ress/electron,electron/electron,seanchas116/electron,bpasero/electron,the-ress/electron,electron/electron,bpasero/electron,gerhardberger/electron,seanchas116/electron,seanchas116/electron,gerhardberger/electron,electron/electron,the-ress/electron,seanchas116/electron,gerhardberger/electron,electron/electron,the-ress/electron,electron/electron,gerhardberger/electron,bpasero/electron,bpasero/electron,gerhardberger/electron,gerhardberger/electron,electron/electron,seanchas116/electron,seanchas116/electron,the-ress/electron,the-ress/electron,the-ress/electron