Fix for dup post change of type losing content

[KevinTriplett]

Fixes #1610:

• Preserve fromPostId in search query param string for duplicated posts while editing
• Adds new function setQuerystringParam to support this preservation
• No new tests added (requiresintegration test?)

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 47.51%. Comparing base (ba370ad) to head (e177420).

:exclamation: Current head e177420 differs from pull request most recent head e72419a. Consider uploading reports for the commit e72419a to get more accurate results

Files	Patch %	Lines
src/util/navigation.js	0.00%	4 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #1613 +/- ## ========================================== - Coverage 47.53% 47.51% -0.02% ========================================== Files 569 569 Lines 13443 13447 +4 Branches 3866 3866 ========================================== Hits 6390 6390 - Misses 7053 7057 +4 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.