Global condition for GetInstanceInfo (ID)

[Causese]

Is your feature request related to a problem? Please describe.

something that I use a lot is for custom checks is:

function()
    local ID = select(3, GetInstanceInfo())
    if ID == 16 then
        return true
    end
end

often times raid difficulty changes how you approach a certain mechanic, the sound you want to play, the text you want to show etc.

it would be neat if there was a global condition for it to save coding time

Describe the solution you'd like
global condition for Normal, Heroic, Mythic Difficulty
14 = Normal
15 = Heroic
16 = Mythic

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.