[lldb] Restructure test folders to match LLDB command hierarchy

Summary:
As discussed on lldb-dev, this patch moves some LLDB tests into a hierarchy that more closely
resembles the commands we use in the LLDB interpreter. This patch should only move tests
that use the command interpreter and shouldn't touch any tests that primarily test the SB API.

Reviewers: #lldb, jfb, JDevlieghere

Reviewed By: #lldb, JDevlieghere

Subscribers: dexonsmith, arphaman, JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D67033

llvm-svn: 370605