[AST Printing] Ensures that ghost annotations are correctly PP

src/kernel_services/ast_printing/printer.ml

tests/pretty_printing/annotations.i

tests/pretty_printing/oracle/annotations.res.oracle

tests/syntax/oracle/ghost_multiline_annot.0.res.oracle

tests/syntax/oracle/ghost_multiline_annot.6.res.oracle

tests/syntax/oracle/ghost_multiline_annot.7.res.oracle

tests/syntax/oracle/ghost_multiline_annot.8.res.oracle