[FEATURE_REQUEST] Shorthand syntax for `execute if function`

[Nico314159]

Description

Minecraft 1.20.3 added the execute if function command, which can be quite useful. JMC does support putting such a condition into an if statement, but we're limited to using the vanilla syntax for the actual condition. Eg:

if (function namespace:my_func) {...}

It seems like a bit of a feature gap that the more intuitive option of

if (my_func()) {...}

is not yet supported. I especially would appreciate being able to use the JMC custom syntax here because I use the this keyword quite often when working in nested folders.