Get rid of kotlinx-coroutines usage in scripting libs and plugins

the dependency on the coroutines library caused various problems like
KT-30778, or stdlib/runtime version conflicts.
The only function used was `runBlocking`, so this change replaces it
with the internal implementation based on the similar internal thing
from the stdlib.
#KT-30778 fixed

libraries/scripting/jvm-host-test/build.gradle.kts

@@ -18,6 +18,7 @@ dependencies {
     testCompile(projectTests(":compiler:tests-common"))
     testCompile(project(":kotlin-scripting-compiler"))
     testCompile(project(":daemon-common")) // TODO: fix import (workaround for jps build)
+    testImplementation(commonDep("org.jetbrains.kotlinx", "kotlinx-coroutines-core"))
 
     testRuntimeOnly(project(":kotlin-compiler"))
     testRuntimeOnly(project(":kotlin-reflect"))