Support expressions in string template

[RZhang05]

Working towards #3579

Description

This PR extends the work in #3585, as planned to support expressions.

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• Targeted PR against feature/string-templates branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

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Additional details and impacted files

@@                     Coverage Diff                     @@
##             feature/string-templates    #3625   +/-   ##
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  Coverage                            ?   80.18%           
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  Files                               ?      412           
  Lines                               ?    95839           
  Branches                            ?        0           
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  Hits                                ?    76850           
  Misses                              ?    16291           
  Partials                            ?     2698           

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unittests	80.18% <ø> (?)

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[SupunS]

Didn't realize this got accidentally closed as well, with the removal of the base branch. Apologies for that!

Now that feature/string-templates branch got merged to master (#3660), @RZhang05 can you rebase this against the master branch?

[SupunS]

haha, this keeps getting closed (unintentionally) 😄

Seems it's not possible to reopen/change-base without reviving the removed branch. Maybe open a new PR from the same existing branch targeting master. Or if that doesn't work, cherry-pick the commits and open a new PR.

Sorry about the extra work.

[turbolent]

Argh, sorry, my bad! I thought all work related to string interpolation was complete, I didn't realize there was another PR.