[lldb] Add missing StringExtras.h includes

In preparation for removing the #include "llvm/ADT/StringExtras.h"
from the header to source file of llvm/Support/Error.h, first add in
all the missing includes that were previously included transitively
through this header.

This is fixing all files missed in b0abd489, 39d8e6e2,
a11efd49, and 5551657b.

Differential Revision: https://reviews.llvm.org/D155018