v0.5.0-pre4-test: build: switch to released gcmodule fork

Destructure improvements

• Support destructuring of function arguments:

local myFn({field}) = field;

myFn({field: 3}) == 3

• Object destructuring defaults

local {
  a,
  b = 20,
  c = 30, 
} = { a: 1, b: 2 };

a == 1 && b == 2 && c == 30

Release preparations

• Remove gcmodule git dependency (replaced with forked and rebranded package)