[DWARFLinker][NFC] Rename libraries to match with directories name. (#77592)

It was noted that new DWARFLinker libraries do not follow naming
agreement -
https://github.com/llvm/llvm-project/pull/75925#issuecomment-1883301659
This patch rename libraries to match with the agreement.

Rename LLVMDWARFLinkerBase library into the LLVMDWARFLinker. Rename
LLVMDWARFLinker library into the LLVMDWARFLinkerClassic. Correct include
path according to the new directory structure.