Use Swift Script to generate the iOS project instead of Bash Script

[suho]

Why

Currently, the iOS templates is moving from Bash to Swift to generate the project. It's better to have the same approach in this templates.

Who Benefits?

Developers

[luongvo]

How about using Kotlin script as the main purpose of KMM is to leverage Kotlin lang? 💭

[suho]

@luongvo This issue is an idea, so it's even better to use Kotlin script for the KMM templates. However, as we have a git submodule for the iOS project, so maybe the kmm templates can reuse the script for iOS templates (e.g., .ios/script.swift)