#83: Create a Spike for error handling

[benedeki]

• new functions null_col and call_udf - needed for other parts of error handling
• ErrorMessage refactoring
• ErrorHandling trait designed to serve as the interface for different implementations
• Implement error handling by putting the info into column of ErrorMessage array
• numerous support classes
  • ErrorColumn to ensure type safety when working with columns with errors reported
  • trait ColumnOrValue and implementing classes to represent a constant value or column value, when a call to add an error column
  • trait ErrorMessageSubmit and its implementation to group together information for error submitting
  • case class ErrorWhen to represent a conditional error submission

[lsulak]

Review finished for now - I like all of this, we had a call of two about all this and we agreed that some things will be refactored / documented / improved in near future outside of this PR.

Once you address my last comments, please let me know so that I can quickly take a look and then approve.

[github-actions[bot]]

JaCoCo code coverage report - scala:2.11 - spark:2.4

File	Coverage [94.21%]	:green_apple:
ErrorMessageSubmitOnMoreColumns.scala	100%	:green_apple:
ErrorMessageSubmitJustErrorValue.scala	100%	:green_apple:
ErrorMessageSubmitOnColumn.scala	100%	:green_apple:
ErrorMessageSubmitWithoutColumn.scala	100%	:green_apple:
ErrorHandlingCommon.scala	100%	:green_apple:
ErrorMessage.scala	100%	:green_apple:
ErrorWhen.scala	100%	:green_apple:
ErrorMessageArray.scala	99.25%	:green_apple:
functions.scala	97.21%	:green_apple:
ColumnOrValue.scala	96.58%	:green_apple:
EvaluateIntoErrorMessage.scala	95.24%	:green_apple:
ErrorHandling.scala	83.82%	:green_apple:
types.scala	61.54%	:x:
EvaluateViaUdf.scala	0%	:x:
ErrorMessageSubmit.scala	0%	:x:
CallUdfAdapter.scala	0%	:x:

Total Project Coverage	81.99%	:green_apple:

[github-actions[bot]]

JaCoCo code coverage report - scala:2.12 - spark:3.3

File	Coverage [94.51%]	:green_apple:
ErrorMessageSubmitOnMoreColumns.scala	100%	:green_apple:
ErrorMessageSubmitJustErrorValue.scala	100%	:green_apple:
ErrorMessageSubmitOnColumn.scala	100%	:green_apple:
ErrorMessageSubmitWithoutColumn.scala	100%	:green_apple:
ErrorHandlingCommon.scala	100%	:green_apple:
ErrorHandling.scala	100%	:green_apple:
ErrorMessage.scala	100%	:green_apple:
ErrorWhen.scala	100%	:green_apple:
functions.scala	100%	:green_apple:
ErrorMessageArray.scala	99.15%	:green_apple:
ColumnOrValue.scala	96.62%	:green_apple:
EvaluateIntoErrorMessage.scala	95.24%	:green_apple:
types.scala	61.54%	:x:
EvaluateViaUdf.scala	0%	:x:
ErrorMessageSubmit.scala	0%	:x:

Total Project Coverage	85.29%	:green_apple: