Add `allow-time-gaps` flag

[Alomir]

THIS TICKET IS NOT YET READY

Task:

• Add a new context flag allow-time-gaps (default TBD)
• When the flag is FALSE
  • For restart time boundary checks, error instead of warn
  • For climate records, do something appropriate; current candidate is to track total daily time, and make sure the time steps add to 24 hours when the day changes. This might not be sufficient if time steps are variable.
  • Also, check that we don't skip a day in the climate records
• When the flag is TRUE
  • change restart time boundary warnings to info logs (logInfo())
  • have new climate record checks log an info message as well.