Add module name as a prefix to declaration keys in JS translator

This is necessary due to different modules can have same
package declarations. When importing declarations from these
packages, we should distinguish from which module we are importing it.

See KT-18652

js/js.translator/testData/box/multiModule/samePackageNames.kt

@@ -0,0 +1,54 @@
+// EXPECTED_REACHABLE_NODES: 511
+// MODULE: lib1
+// FILE: lib1.kt
+package pkg
+
+object O {
+    fun f() = "O.f"
+}
+
+fun foo() = "foo"
+
+class A {
+    fun f() = "A.f"
+}
+
+// MODULE: lib2
+// FILE: lib2.kt
+package pkg
+
+object P {
+    fun f() = "P.f"
+}
+
+fun bar() = "bar"
+
+class B {
+    fun f() = "B.f"
+}
+
+// MODULE: main(lib1, lib2)
+// FILE: main.kt
+import pkg.*
+
+fun box(): String {
+    var r = O.f()
+    if (r != "O.f") return "fail1: $r"
+
+    r = foo()
+    if (r != "foo") return "fail2: $r"
+
+    r = A().f()
+    if (r != "A.f") return "fail3: $r"
+
+    r = P.f()
+    if (r != "P.f") return "fail4: $r"
+
+    r = bar()
+    if (r != "bar") return "fail5: $r"
+
+    r = B().f()
+    if (r != "B.f") return "fail6: $r"
+
+    return "OK"
+}