Fix Unix epoch time display in case of null endedAt value

[merobi-hub]

Problem

In the case of a fresh instance of Marquez (e.g., a new user experimenting with a quickstart), using cURL to post a start event by itself causes the runs component to display the Unix epoch time in the ENDED AT column.

Solution

This makes displaying the endedAt value conditional on there being a durationMs value greater than 0. Otherwise, it will display 'N/A'.

Note: All database schema changes require discussion. Please link the issue for context.

One-line summary: Fixes Unix epoch time display in case of null endedAt value.

Closes: #2646

Checklist

• You've signed-off your work
• Your changes are accompanied by tests (if relevant)
• Your change contains a small diff and is self-contained
• You've updated any relevant documentation (if relevant)
• You've included a one-line summary of your change for the CHANGELOG.md (Depending on the change, this may not be necessary).
• You've versioned your .sql database schema migration according to Flyway's naming convention (if relevant)
• You've included a header in any source code files (if relevant)

[netlify]

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[codecov]

Codecov Report

Merging #2647 (616f678) into main (fd4d1c3) will decrease coverage by 3.09%.
The diff coverage is n/a.

❗ Current head 616f678 differs from pull request most recent head cd5e1b1. Consider uploading reports for the commit cd5e1b1 to get more accurate results

@@             Coverage Diff              @@
##               main    #2647      +/-   ##
============================================
- Coverage     83.35%   80.26%   -3.09%     
+ Complexity     1295      232    -1063     
============================================
  Files           244       43     -201     
  Lines          5948      968    -4980     
  Branches        279       38     -241     
============================================
- Hits           4958      777    -4181     
+ Misses          844      162     -682     
+ Partials        146       29     -117     

see 201 files with indirect coverage changes

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[phixMe]

Thanks @merobi-hub