To show symbolic link files indication on OpenGrok XREF navigation pages

[tonzhao]

Is your feature request related to a problem? Please describe.
Navigating in OpenGrok, it's not clear when files/folders are symlinked. This causes a lot of confusion for those who don't know.

Describe the solution you'd like
I would like the xref navigation page to appear similar to the effect of "ls -lp" in linux to explicitly indicate symlinks.
e.g.

	bazel/	
	bazel_common_rules/	
	blueprint/	
	core -> make/core/	
	make/	
	orchestrator/	
	pesto/	
	soong/	
	target -> make/target/	
	tools -> make/tools/
	CleanSpec.mk -> make/CleanSpec.mk	
	buildspec.mk.default -> make/buildspec.mk.default	
	envsetup.sh -> make/envsetup.sh

Describe alternatives you've considered
None

Additional context
None