Dynamic breakpoint support

[TwitchBronBron]

This adds support for dynamic breakpoints over the debug protocol.

• [x] dynamically add and remove breakpoints during active session
• [ ] set initial breakpoints during app launch
• [ ] support stopOnEntry using dynamic breakpoint instead of injected stop
• [ ] fix race condition where breakpoint placed on first few lines of main function won't suspend
• [ ] only allow breakpoints in xml/brs files (after mapping bp to staging location)
• [ ] investigate what happens if we send the same breakpoint with the same id and location twice.
• [ ] Verify breakpoint in same file across sourceDirs don't get duplicated

[TwitchBronBron]

Closing this in favor of #84