Always output no-update fragment on the server

[DylanPiercey]

Description

This fixes an issue where no-update can cause the structure to change in a browser vs a server render causing some SSR'd dom to be incorrectly removed. Now we always output fragment markers for SSR'd no-update content to maintain a consistent structure.

Checklist:

• I have read the CONTRIBUTING document and have signed (or will sign) the CLA.
• I have updated/added documentation affected by my changes.
• I have added tests to cover my changes.

[codecov]

Codecov Report

Merging #1498 into master will decrease coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master   #1498      +/-   ##
=========================================
- Coverage    90.5%   90.5%   -0.01%     
=========================================
  Files         352     352              
  Lines       12586   12583       -3     
=========================================
- Hits        11391   11388       -3     
  Misses       1195    1195

Impacted Files	Coverage Δ
src/core-tags/components/preserve-tag.js	100% <100%> (ø)	⬆️

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