fix: format decimal to string when casting to short

[manuzhang]

Which issue does this PR close?

Closes #2914.

Rationale for this change

What changes are included in this PR?

How are these changes tested?

Updated CometCastSuite.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 59.62%. Comparing base (f09f8af) to head (9064dfd).
⚠️ Report is 793 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2916      +/-   ##
============================================
+ Coverage     56.12%   59.62%   +3.49%     
- Complexity      976     1382     +406     
============================================
  Files           119      167      +48     
  Lines         11743    15492    +3749     
  Branches       2251     2568     +317     
============================================
+ Hits           6591     9237    +2646     
- Misses         4012     4955     +943     
- Partials       1140     1300     +160     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[manuzhang]

@rohitrastogi @andygrove Please help review when you find time. Thanks!

[andygrove]

@manuzhang I pulled these test changes locally using latest from main branch and they pass for me, so I'm not sure that these tests reproduce the problem that the fix is intended to address?

[manuzhang]

@andygrove I've reworked my PR. Could you please check again?

[manuzhang]

Failed test is not related to this PR.

- Comet native operator after ShuffleQueryStage + ReusedExchange (1 second, 108 milliseconds)
Error: Exception in thread "ScalaTest-dispatcher" java.lang.NoClassDefFoundError: $anonfun$doPreserve$1
	at org.scalatest.tools.PrettyPrinter.traverse(PrettyPrinter.scala:155)
	at org.scalatest.tools.PrettyPrinter.format(PrettyPrinter.scala:231)
	at org.scalatest.tools.PrettyPrinter.$anonfun$format$2(PrettyPrinter.scala:267)
	at org.scalatest.tools.PrettyPrinter.$anonfun$format$2$adapted(PrettyPrinter.scala:267)
	at org.scalatest.tools.XmlUtility$.sbToString(XmlUtility.scala:31)
	at org.scalatest.tools.PrettyPrinter.format(PrettyPrinter.scala:267)
	at org.scalatest.tools.JUnitXmlReporter.xmlify(JUnitXmlReporter.scala:385)
	at org.scalatest.tools.JUnitXmlReporter.writeSuiteFile(JUnitXmlReporter.scala:77)
	at org.scalatest.tools.JUnitXmlReporter.apply(JUnitXmlReporter.scala:59)
	at org.scalatest.DispatchReporter$Propagator.$anonfun$run$10(DispatchReporter.scala:249)
	at org.scalatest.DispatchReporter$Propagator.$anonfun$run$10$adapted(DispatchReporter.scala:248)
	at scala.collection.immutable.List.foreach(List.scala:334)
	at org.scalatest.DispatchReporter$Propagator.run(DispatchReporter.scala:248)
	at java.base/java.lang.Thread.run(Thread.java:840)
Caused by: java.lang.ClassNotFoundException: $anonfun$doPreserve$1
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
	... 14 more
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (concurrentHashTable.inline.hpp:678), pid=78523, tid=28931
#  fatal error: aux_index does not match even or odd indices
#
# JRE version: OpenJDK Runtime Environment Zulu17.62+19-CRaC-CA (17.0.17+10) (build 17.0.17+10-LTS)
# Java VM: OpenJDK 64-Bit Server VM Zulu17.62+19-CRaC-CA (17.0.17+10-LTS, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, bsd-aarch64)
# No core dump will be written. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# An error report file with more information is saved as:
# /Users/runner/work/datafusion-comet/datafusion-comet/spark/hs_err_pid78523.log
#
# If you would like to submit a bug report, please visit:
#   http://www.azul.com/support/
#