[CLI] Introduce new compiler arguments for registering compiler plugins

With new syntax each plugin should be registered in separate argument with syntax
`-Xcompiler-plugin=classpath1,classpath2[=argument1=value1,argument2=value2]`

compiler/testData/cli/jvm/plugins/multiplePlugins.kt

@@ -0,0 +1,12 @@
+package foo
+
+annotation class NoArg
+annotation class AllOpen
+
+@AllOpen
+class Base(val s: String)
+
+class Derived(s: String) : Base(s) {
+    @NoArg
+    inner class Inner(val s: String)
+}