Add API to not apply the Compose Compiler plugin

[eymar]

This a solution for #3695

Usage:

compose {
    excludePlatform(KotlinPlatformType.js, KotlinPlatformType.native)
}

or

compose {
    platformTypes.set(platformTypes.get() - setOf(KotlinPlatformType.js, KotlinPlatformType.native))
}

2nd sample seems to be too verbose, so maybe we can make platformTypes private.

---

Note:
this solution will make it possible to disable the Compose Compiler plugin for all targets which have given KotlinPlatformType.
A project can have many targets with the same KotlinPlatformType:

jvm("backend) {}
jvm("frontend") {}
// etc

compose.excludePlatform(KotlinPlatformType.jvm) will disable the compose compiler plugin for all jvm targets.
While we don't have a use case for now where it can be a problem, I wanted to highlight this.

__

As a next iteration we can improve the DSL to something like this:

kotlinCompilerPlugin {
    artifact = "1.5.0"
    args = ""
    platformTypes = setOf()
}