This adds new types for setExceptionBreakpoints and adds support for
`supportsExceptionFilterOptions`, which allows exception breakpoints to
set a condition.
While testing this, I noticed that obj-c exception catch breakpoints may
not be working correctly in lldb-dap.
Convert Breakpoint & Watchpoints structs to classes to provide proper
access control. This is in preparation for adopting SBMutex to protect
the underlying SBBreakpoint and SBWatchpoint.