[SPARK-20951][SQL] Built-in SQL Function FormatNumber validate input value

[wangyum]

What changes were proposed in this pull request?

SQL Function FormatNumber should validate input value, if argument 2 < 0 throw TypeCheckFailure same as Hive's way . after this pr:

spark-sql> select format_number(12332.123456, -4);
Error in query: cannot resolve 'format_number(12332.123456BD, -4)' due to data type mismatch: Argument 2 of function FORMAT_NUMBER must be >= 0, but -4 was found; line 1 pos 7;
'Project [unresolvedalias(format_number(12332.123456, -4), None)]
+- OneRowRelation$

spark-sql> 

How was this patch tested?

unit tests

[SparkQA]

Test build #77637 has finished for PR 18175 at commit 655ec8f.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.