'next gui slot' expression

[Fusezion]

Description

Currently, we're only able to use format next gui slot... I feel like adding the expression for it would provide slightly more customization for more usages

for example let's say I'm making a skript where I'm formatting multiple gui slots based off the next gui location

(current location is 10) but I'm formatting gui slot 10, 19, 28 and 37 and so one for 6 more slots
to do this we're currently needing to do

loop (integers from 10 to 16):
  format gui slot loop-value...
  format gui slot loop-value+9...
  format gui slot loop-value+18...
  format gui slot loop-value+27...

I feel like being able to do

loop 7 times:
  format gui slot index of next gui slot+27...
  format gui slot index of next gui slot+18...
  format gui slot index of next gui slot+9...
  format next gui slot...

would prove easier on longer stuff like this and just feels better and with something like this I truly believe we'll see many more uses

[APickledWalrus]

Will be added in the next release