[data-export] Local browser time config option

[dmoruzzi]

Describe your changes

Add an option to convert UTC time to local browser time for Data Export.

Issue ticket number and link

Issue: #527

Checklist before requesting a review

• I have read and understand the Contributions section
• Target branch is releaseCandidate and not master
• I have performed a self-review of my code
• I ran the unit tests and my PR does not break any tests
  • TEST data-export fails with the current edition of the releaseCandidate. My changes did not contribute to any new failures.
• I documented the changes I've made on the CHANGES.md and followed actual conventions
• I added a new section on how-to.md (optional)
  • I used ../assets/images/how-to/show-local-time.png?raw=true for my documentation reference images. If something like https://github.com/tprouvot/Salesforce-Inspector-reloaded/assets/{ID}/{UUID} is more appropriate, please provide instructions and I'll get this updated.

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Notes

• the offsetMinutes calculations and time reshuffling is necessary to accommodate 30 and 45 minute offsets for time zones.
• time conversion is disabled by default to avoid disrupting workflows.

[dmoruzzi]

Partially related to #496. I felt a toggle for all was more meaningful as it allowed me to quickly compare multiple rows at the same time.

[tprouvot]

Thanks for the PR @dmoruzzi, I'll check this in details but looks good to me!