[lldb] Move ScriptInterpreter Interfaces to subdirectory (NFC)

As we're consolidating and  streamlining the various scripting
affordances of lldb, we keep creating new interface files.

This patch groups all the current interface files into a separate sub
directory called `Interfaces` both in the core `Interpreter` directory
and the `ScriptInterpreter` plugin directory.

Differential Revision: https://reviews.llvm.org/D158833



Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>