Usage of `vararg` results in uncompilable code

[tyuldashev]

Description

In case user have functions with vararg UTBot tries to pass Array as parameter which doesn't work

To Reproduce

Steps to reproduce the behavior:

1. In UTBot settings set Generated test language to Kotlin other leave default
2. Generate tests for following code

class VarArgs {
    fun sum(vararg ints:Int): Int {
        var sum: Int = 0
        for (i in ints) sum += i
        return sum
    }
}

Expected behavior

Compilable tests are supposed to be generated.

Actual behavior

Generated tests are not compilalbe and look like:

@Test
fun testSum1() {
    val varArgs = VarArgs()
    val ints = intArrayOf(1, 1409199696, 1)
    
    val actual = varArgs.sum(ints)
    assertEquals(1409199698, actual)
}

Visual proofs (screenshots, logs, images)

[EgorkaKulikov]

First of all, we should investigate, how to define that vararg is used. It is not so obvious looking at bytecode.
After that, be careful with spread operator and it's possible deprecations in some cases.