Recommit r315087 "[refactor] add support for refactoring options"

The recommit fixes a UB bug that occurred only on a small number of bots.

Original message:

This commit adds initial support for refactoring options. One can now use
optional and required std::string options.

This commit also adds a NewNameOption for the local-rename refactoring action to
allow rename to work with custom names.

Differential Revision: https://reviews.llvm.org/D37856

llvm-svn: 315661