fixes nim-lang/nimsuggest#119 outline includes (#16608)

nimsuggest outline should account for includes, now it does:
- the module prefix will be of the module doing the including
- the filename will be of the module that was included
- adds a test case for it

nimsuggest/tests/tinclude.nim

@@ -1,4 +1,6 @@
-# import that has an include, def calls must work into and out of includes
+# import that has an include:
+# * def calls must work into and out of includes
+# * outline calls on the import must show included members
 import fixtures/minclude_import
 
 proc go() =
@@ -8,12 +10,16 @@ go()
 
 discard """
 $nimsuggest --tester $file
->def $path/tinclude.nim:5:14
+>def $path/tinclude.nim:7:14
 def;;skProc;;minclude_import.create;;proc (greeting: string, subject: string): Greet{.noSideEffect, gcsafe, locks: 0.};;*fixtures/minclude_include.nim;;3;;5;;"";;100
 >def $path/fixtures/minclude_include.nim:3:71
 def;;skType;;minclude_types.Greet;;Greet;;*fixtures/minclude_types.nim;;4;;2;;"";;100
 >def $path/fixtures/minclude_include.nim:3:71
 def;;skType;;minclude_types.Greet;;Greet;;*fixtures/minclude_types.nim;;4;;2;;"";;100
+>outline $path/fixtures/minclude_import.nim
+outline;;skProc;;minclude_import.say;;*fixtures/minclude_import.nim;;7;;5;;"";;100
+outline;;skProc;;minclude_import.create;;*fixtures/minclude_include.nim;;3;;5;;"";;100
+outline;;skProc;;minclude_import.say;;*fixtures/minclude_import.nim;;13;;5;;"";;100
 """
 
 # TODO test/fix if the first `def` is not first or repeated we get no results