Implement run now/trigger now mode in UI

[shahzad31]

This is an extension of one shot mode in the UI which was added while adding/editing monitors. Those test runs doesn't appear in actual results.

Run now mode will be handled from the overview list.

Basic use case is that, user sees a monitor up/down and they want to trigger a run for that, essentially bypassing it's scheduled run.

1. Monitor should run and display results as soon as the result is completed
2. Result should become part of history
3. Show progress if possible via toast etc

There are two places this will be done. First in the overview monitor list and also can be triggered from monitor detailed page.