Updating timer class

[landinjm]

• Please check if the PR fulfills these requirements

• The PR follows our guidelines (formatting & style)
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  Removing the previous PR that prints total wall-time in favor of the dealii::TimerOutput summary at the end of the simulation. The reason why we haven't done this is because the output doesn't sort the section based on the depth they are called, leading to confusing results. Caliper fixes the issue, but we need to manually sort the entries to provide an intelligible output.

• What is the current behavior? (You can also link to an open issue here)
  We simply print out all timing behavior, unsorted.

• What is the new behavior (if this is a feature change)?
  A summary of the section, times, and number of calls is provided.

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)
  No

• Other information: