Better support for `--preserve-routine` in `clang_delta`

[aytey]

In #44, functionality was introduced that allowed the user to run clang_delta (with --transformation=replace-function-def-with-decl), but to say "do not change this routine".

We have a few extensions that are worth implementing:

• [ ] Extend --query-instances to not only print the instance count, but also the names of the possible routines (which then allows a user to know which name to use as part of --preserve-routine).
• [ ] Support the use of the "full" name (e.g., in the case of templated methods in C++) -- currently templated names do not use the full expansion
• [ ] Allow the user to provide a regex over a simple string, and therefore preserve any matching routine