JS BE: expose imported modules via $$importsForInline$$ property

... and use it as prefix to FQN in inline functions. This allows
to properly inline function declared in module A to module B,
when this function calls another function in module C.

See KT-18201

js/js.translator/testData/box/incremental/multipleReimport.kt

@@ -0,0 +1,24 @@
+// EXPECTED_REACHABLE_NODES: 491
+// MODULE: lib1
+// FILE: lib1.kt
+
+fun foo() = "O"
+
+fun bar() = "K"
+
+// MODULE: lib2(lib1)
+// FILE: lib2a.kt
+// PROPERTY_WRITE_COUNT: name=lib1 count=1
+// PROPERTY_WRITE_COUNT: name=$$imports$$ count=1
+
+inline fun o() = foo()
+
+// FILE: lib2b.kt
+
+inline fun k() = bar()
+
+// MODULE: main(lib2)
+// FILE: main.kt
+// RECOMPILE
+
+fun box() = o() + k()