[FIR] Include generated declarations into FIR dump in tests

Also include non root package directive of FirFile to dump

compiler/fir/analysis-tests/testData/resolve/multifile/simpleStarImport.fir.txt

@@ -1,4 +1,6 @@
 FILE: B.kt
+    package b.d
+
     public abstract expect interface Other : R|kotlin/Any| {
     }
     public final expect class Another : R|kotlin/Any| {
@@ -6,6 +8,8 @@ FILE: B.kt
     public final fun baz(): R|kotlin/Unit| {
     }
 FILE: A.kt
+    package a.d
+
     public final fun foo(arg: R|b/d/Other|): R|b/d/Another|
     public final fun bar(): R|kotlin/Unit| {
         R|b/d/baz|()