[BUG] Issues found by Spark UT Framework on RapidsJsonExpressionsSuite

[binmahone]

Describe the bug

Spark UT Framework enabled RapidsJsonExpressionsSuite(#10851) with the following test cases explicitly excluded:

• from_json - invalid data
  Parsing a column containing invalid json into StructureType with schema throws an Exception. #10891
• from_json - input=empty array, schema=struct, output=single row with null
  from_json function parses a column containing an empty array, throws an exception. #10907
• from_json - input=empty object, schema=struct, output=single row with null
  from_json, when input = empty object, rapids throws an exception. #10910
• SPARK-20549: from_json bad UTF-8
  from_json: when input is a bad json string, rapids would throw an exception. #10911
• from_json with timestamp
• to_json - array
  to_json when converts an array will throw an exception: #10915
• to_json - empty array
  to_json when converts an empty array into json throws an exception.  #10924
• to_json - array with single empty row
  to_json function to convert the array with a single empty row to a JSON string throws an exception. #10923
• to_json with timestamp
• SPARK-21513: to_json support map[string, struct] to json
  to_json function doesn't support map[string, struct] to json conversion. #10916
• ** SPARK-21513: to_json support map[struct, struct] to json
  to_json when parsing a map[struct, struct] throws an exception. #10918
• SPARK-21513: to_json support map[string, integer] to json
  to_json converting map[string, integer] to json, throws an exception #10919
• to_json - array with maps
  to_json converting an array with maps throws an exception. #10920
• to_json - array with a single map
  to_json - array with single map #10921
• from_json missing fields
  from_json with predefined schema when converts json with missing fields, throwing an exception. #10922

These excluded test cases needs further investigating!!!
Notice: Other test cases in this suite may pass with falling back!

Steps/Code to reproduce bug

1. Compile everything with mvn -Dbuildver=330 install -DskipTests
2. Pick a test case name in the above table
3. Go to RapidsTestSettings and find the line starting with ".exclude" and containing the test case name, comment it out
4. Run the Suite then you'll see one failed test case. E.g. mvn -nsu -Dbuildver=330 -pl tests -Dsuites="org.apache.spark.sql.rapids.suites.RapidsXXXSuite" test (replace RapidsXXXSuite with the right name in issue header). ALWAYS double check if your suite name coincide with in source code, as it may contain typos!

Expected behavior
The suite can pass without excluding any test case.