[DWARF] Change to consistently print out abbrev code in .debug_names (#68353)

Changed so that when Abbrev code is printed out for entry it is done in
the same
way as in Abbrev table.
Once letters are present in a hex number in abbrev table they will be
lower case,
and in the Entry upper case. Which makes FIleCheck Pattern recognition
fail.
Example in: llvm/test/tools/llvm-dwarfdump/X86/debug-names-misaligned.s