Skip empty run rates

[peterfpeterson]

This verifies that there are any runs during the requested time period before running the stored procedure call and/or the hand written version. This should have an immediate effect of speeding up instruments that aren't measuring data (e.g. NOW*) and make the extended dashboard faster.

DO NOT MERGE BEFORE #219

Check all that apply:

• updated documentation
• Source added/refactored
• Added unit tests
• Added integration tests
• (If applicable) Verified that manual tests requiring the /SNS and /HFIR filesystems pass without fail

References:

• Links to IBM EWM items:
• Links to related issues or pull requests:

Manual test for the reviewer

(Instructions for testing here)

Check list for the reviewer

• best software practices
  • clearly named variables (better to be verbose in variable names)
  • code comments explaining the intent of code blocks
• All the tests are passing
• The documentation is up to date
• code comments added when explaining intent

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.90%. Comparing base (597cafd) to head (5fe229f).

Additional details and impacted files

@@            Coverage Diff             @@
##             next     #222      +/-   ##
==========================================
+ Coverage   77.83%   77.90%   +0.06%     
==========================================
  Files          54       54              
  Lines        4724     4738      +14     
==========================================
+ Hits         3677     3691      +14     
  Misses       1047     1047              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[backmari]

The changes should improve performance by skipping collecting histogram data for runs per hour if there are no runs/errors in the last 24 hours.
I have tested locally that the runs per hour plots work both for instruments with and without runs and errors in the last 24 hours.