update replacementHandler function

[alfatahh54]

I fixed the replacementHandler function so that it can execute js script with the marker "{{..}}"

example:
const transformationMapping = {
name: {
first_name: 'John',
last_name: 'Doe'
},
age: 30,
profession: 'Designer'
}

const input ="Hallo, my name {{name.first_name + ' ' + name.last_name}}. I am {{age}} years old, and my profession is {{profession}}"
const result = replacementHandler(input, exampleObject)
console.log(result)

it will show result with value "Hallo, my name John Doe. I am 30 years old, and my profession is Designer"