[lldb/API] Expose Module::IsLoadedInTarget() to SB API (NFC)

This patch adds an `SBTarget::IsLoaded(const SBModule&) const` endpoint
to lldb's Scripting Bridge API. As the name suggests, it will allow the
user to know if the module is loaded in a specific target.

rdar://37957625

Differential Review: https://reviews.llvm.org/D95686



Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>