[ASTMatchers] Add traversal-kind support to `DynTypedMatcher`

Summary:
This patch exposes `TraversalKind` support in the `DynTypedMatcher` API. While
previously, the `match` method supported traversal logic, it was not possible to
set or get the traversal kind.

Reviewers: gribozavr, steveire

Subscribers: hokein, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D80685