Add assertEqual function to KCL stdlib (#3279)

Takes a tolerance, because floating-point imprecision.

src/wasm-lib/tests/executor/inputs/computed_var.kcl

@@ -4,8 +4,7 @@ const arr = [0, 0, 0, 10]
 const i = 3
 const ten = arr[i]
 
-assertLessThanOrEq(ten, 10, "oops")
-assertGreaterThanOrEq(ten, 10, "oops2")
+assertEqual(ten, 10, 0.000001, "oops")
 
 const p = "foo"
 const obj = {
@@ -14,5 +13,4 @@ const obj = {
 }
 const one = obj[p]
 
-assertLessThanOrEq(one, 1, "oops")
-assertGreaterThanOrEq(one, 1, "oops2")
+assertEqual(one, 1, 0.0000001, "oops")