TrigCost: Add Sequence cost summary

Add a sequence cost summary based on algorithm summary histograms.

For each sequence, the list of algorithms is read from the menu saved in the metadata. Then the values are processed:

• Active events - sequence was active if at least one of algorithms was active (max(algorithms active events))
• calls per event - sequence was called if at least one of algorithms was active (max(algorithms calls per event))
• slow calls - sum of the slow calls of all the algorithms
• event/call rate - sequence is called as often as the algorithms: (max(algorithms event/call rate))
• total time - sum of the time of all the algorithms
• total time % - percentage total time of all the sequence algorithms
• total time per call / per event - mean sequence total time per call is equal to mean time of all the algorithm's calls
• Run Algs/Event - the sum of the events where sequence's algorithms were active / number of events where sequence was active

Tagging @tamartin @mark