fix(legacy-plugin-chart-calendar): fix timestamp timezone in Calendar

[kgabryje]

SUMMARY

Previously, the tooltips in Calendar Heatmap chart where displaying the date with user's local timezone applied. So for instance, if the query returned a date "2015-01-01 00:00:00", for a user in Poland the tooltip would be "2014-12-31 23:00:00" because of the timezone.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

Before:

After:

TESTING INSTRUCTIONS

1. Create a Calendar Heatmap chart
2. Verify that the dates in the calendar are UTC

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

CC @junlincc

Internal: https://app.shortcut.com/preset/story/32292/fix-timezone-bug-on-cal-heatmap

[kgabryje]

/testenv up

[github-actions]

@kgabryje Ephemeral environment spinning up at http://34.222.48.144:8080. Credentials are admin/admin. Please allow several minutes for bootstrapping and startup.

[codecov]

Codecov Report

Merging #17664 (a77f061) into master (07e8837) will increase coverage by 0.01%.
The diff coverage is 25.00%.

@@            Coverage Diff             @@
##           master   #17664      +/-   ##
==========================================
+ Coverage   68.76%   68.78%   +0.01%     
==========================================
  Files        1596     1597       +1     
  Lines       65221    65222       +1     
  Branches     6949     6950       +1     
==========================================
+ Hits        44849    44862      +13     
+ Misses      18489    18475      -14     
- Partials     1883     1885       +2     

Flag	Coverage Δ
javascript	57.46% <25.00%> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ugins/legacy-plugin-chart-calendar/src/Calendar.js	0.00% <0.00%> (ø)
...legacy-plugin-chart-calendar/src/transformProps.js	0.00% <0.00%> (ø)
.../plugins/legacy-plugin-chart-calendar/src/utils.ts	40.00% <40.00%> (ø)
...src/components/FilterableTable/FilterableTable.tsx	72.31% <0.00%> (+5.45%)	⬆️

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[villebro]

Finally, thanks so much for squashing this annoying bug that's practically always been there! 🐛 Just one thought: should we start relocating viz plugin tests next to the code in the source folders, like we're doing on the frontend side of the codebase?

[github-actions]

Ephemeral environment shutdown and build artifacts deleted.