Add a new debug configuration for squash server.

Add a debug config to squash. A debug config instrucs squash what containers should be debugged, and now. DebugConfig object consists of:

• Attachment: The object we are attaching to. either a specific container, or a service. in the case of the service, the squash will attach to the first container that hits a debug event.
• Breakpoints: A list of breakpoints. When "immediately" set to false, squash will wait for a debug event (i.e a program crash) before giving the user access to the remote debugger. If breakpoints is set, squash will place them and will notify when the first breakpoint hits.
• image: The container image we are debugging. this is used for extra validation, as placing breakpoints on the wrong binary can lead to unexpected results.
• debugger: Type of debugger to use. "dlv" and "gdb" are supported now.
• immediately: Weather to attach immediatly or wait for debug event. can only be set to true if attachment type is container.