Support both "skip" and "times" for a single fail point

It'd be useful for some new drivers tests to set fail points like:

{

  configureFailPoint: "failCommand",

  mode: { times: 1, skip: 1 },

  data: { failCommands: ["insert"], errorCode: 11600

}

This should allow one insert command to execute, fail the second insert command with error code 11600, and then allow all future insert commands to execute normally.