Support for Kotlin scripts

[jmfayard]

I propose we add first-class support for Kotlin scripts because life is too short for Bash programming.

FeatureFlag

KOTLIN_SCRIPTS, disabled by default

see pr #583

refreshVersions

./gradlew refreshVersions --enable KOTLIN_SCRIPTS should show updates
Initial:

#!/usr/bin/env kotlin  
  
@file:Repository("https://jitpack.io")  
@file:DependsOn("io.rsocket.kotlin:rsocket-core-jvm:0.13.0-SNAPSHOT")  
@file:DependsOn("io.ktor:ktor-client-okhttp:1.5.2")  
@file:DependsOn("com.squareup.wire:wire-moshi-adapter:3.4.0")  
@file:CompilerOptions("-jvm-target", "17")

• mavenCentral() should be supported by default
• @file:Repository(..) should be supported if present

Expected:

#!/usr/bin/env kotlin  
  
@file:Repository("https://jitpack.io")  
@file:DependsOn("io.rsocket.kotlin:rsocket-core-jvm:0.13.0-SNAPSHOT")  
////                                    # available:0.15.0")  
////                                    # available:0.16.0")  
@file:DependsOn("io.ktor:ktor-client-okhttp:1.5.2")  
////                            # available:1.6.0")  
////                            # available:1.7.0")  
@file:DependsOn("com.squareup.wire:wire-moshi-adapter:3.4.0")  
@file:CompilerOptions("-jvm-target", "17")

refreshVersionsCleanUp

./gradlew refreshVersionsCleanUp --enable KOTLIN_SCRIPTS should remove the comments

Initial:

#!/usr/bin/env kotlin  
  
@file:Repository("https://jcenter.bintray.com")  
//// somme comment
@file:DependsOn("io.rsocket.kotlin:rsocket-core-jvm:0.13.0-SNAPSHOT")  
////                                    # available:0.14.0")  
////                                    # available:0.15.0")  
@file:DependsOn("io.ktor:ktor-client-okhttp:1.5.2")  

Expected:

#!/usr/bin/env kotlin  
  
@file:Repository("https://jcenter.bintray.com")  
@file:DependsOn("io.rsocket.kotlin:rsocket-core-jvm:0.13.0-SNAPSHOT")  
@file:DependsOn("io.ktor:ktor-client-okhttp:1.5.2")  

Old PR

See #517