Rename stage_limiter! and step_limiter! and make them available wherever possible

[ranocha]

As discussed with @ChrisRackauckas on Slack:

• stage_limiter! - could be stage_callback!
• step_limiter! - could be step_callback! but then it could be easy to be confused with standard callbacks

It would also be very useful if these were added wherever possible - in particular also to implicit methods etc.

However, the renaming part will be a breaking change (or needs to be deprecated first).