Fix formatter spacing around path separators in macro arguments

[kbrunham-intel]

Summary

• Stops the formatter from treating / between identifiers in macro arguments as a division operator.
• Paths such as `PROJECT_INCLUDE(`PATH_MY_MODULE/src/config_class.sv) stay compact instead of becoming `PATH_MY_MODULE / src / config_class.sv, which does not compile.
• Division outside macros is unchanged (assign x = a/b; still becomes a / b).
• Adds token-annotator and formatter regression tests.

Fixes #2352

Test plan

• bazel test -c opt //verible/verilog/formatting:token-annotator_test //verible/verilog/formatting:formatter_test
• Original verible-verilog-format inserting spaces around *nix path separators, resulting in compile errors. #2352 sample formats without spaces around /
• CI on this PR is green

[kbrunham-intel]

Hi @hzeller. Please consider this change which addresses issue 2352 with the formatter.