[TEST] Invert dependency between :test-generator and :tests-common modules

This is needed to provide ability for declaring new implementations of
  test generators, based on existing infrastructure, which won't add
  dependency on :compiler:tests-common

Also this commit removes implicit dependency on :compiler:tests-common
  from :compiler:tests-common-new

libraries/tools/kotlinp/build.gradle.kts

@@ -23,6 +23,7 @@ dependencies {
     testCompileOnly(project(":kotlinx-metadata"))
     testCompileOnly(project(":kotlinx-metadata-jvm"))
     testCompile(commonDep("junit:junit"))
+    testCompile(projectTests(":compiler:tests-common"))
     testCompile(projectTests(":generators:test-generator"))
 
     testRuntime(project(":kotlinx-metadata-jvm", configuration = "runtime"))

libraries/tools/kotlinp/test/org/jetbrains/kotlin/kotlinp/test/GenerateKotlinpTests.kt

@@ -5,7 +5,7 @@
 
 package org.jetbrains.kotlin.kotlinp.test
 
-import org.jetbrains.kotlin.generators.generateTestGroupSuite
+import org.jetbrains.kotlin.generators.impl.generateTestGroupSuite
 
 fun main(args: Array<String>) {
     System.setProperty("java.awt.headless", "true")