[AURON#1327] Implement native function of round

[slfan1989]

Which issue does this PR close?

Closes #1327.

Rationale for this change

spark_round is a Rust implementation of an Apache Spark-style round function for the DataFusion query engine. Its primary purpose is to perform rounding operations on numerical values, adhering to Spark's HALF_UP rounding mode (i.e., 0.5 rounds to 1, -0.5 rounds to -1). It supports multiple data types (Float64, Float32, Int16, Int32, Int64, Decimal128) and can handle negative precision and null values.

What changes are included in this PR?

• We implemented the Round function following Spark’s HALF_UP rounding semantics,
  ensuring full behavioral alignment with Spark SQL.

• For validation, we directly reused the unit tests from MathExpressionsSuite#round/bround,
  comparing our implementation against Spark’s native results using:

checkEvaluation(Round(doublePi, scale), doubleResults(i), EmptyRow)
checkEvaluation(Round(shortPi, scale), shortResults(i), EmptyRow)
checkEvaluation(Round(intPi, scale), intResults(i), EmptyRow)
checkEvaluation(Round(longPi, scale), longResults(i), EmptyRow)
checkEvaluation(Round(floatPi, scale), floatResults(i), EmptyRow)

• We also added additional boundary test cases to ensure that spark_round
  behaves correctly under edge conditions such as large numbers, small numbers, and negative scales.

Are there any user-facing changes?

No.

How was this patch tested?

Unit Test.

[slfan1989]

@richox @cxzl25 Could you please help review this PR? Thanks a lot!

In #1327, I conducted a detailed comparison between Spark and DataFusion regarding the behavior of the Round function. After identifying the differences, I implemented this version by referring to the implementation of other functions, such as spark_sha2. This implementation has been verified with Spark’s unit tests, and the results are as expected.

[zuston]

looks good, if we could involve the more spark tests here, it will be better.

[slfan1989]

looks good, if we could involve the more spark tests here, it will be better.

@zuston Thank you very much for reviewing the code. I have implemented the Spark validation logic based on your suggestions, and it runs as expected in local testing.

[slfan1989]

@richox @cxzl25 @zuston Could you please review this PR? Thank you very much!

[zuston]

@richox @cxzl25 @zuston Could you please review this PR? Thank you very much!

Merged. Thanks for your contribution! @slfan1989

[slfan1989]

@richox @cxzl25 @zuston Could you please review this PR? Thank you very much!

Merged. Thanks for your contribution! @slfan1989

Thank you very much for reviewing the code!