Invalid Count - Add verbosity options and clarification

[GeekSheikh]

The current Invalid Count report metric is confusing. ValidNumerics and ValidStrings use "collect_set" while Bounds rules utilize aggs and report back a 1 as well. These design decisions were made initially for performance on large datasets.

Use the RuleSet().validate function attribute of detailLevel to allow the user to specify the report detail level. Higher levels == longer run times but more detail. Great for dev stages.

dataframe-rules-engine/src/main/scala/com/databricks/labs/validation/RuleSet.scala

Lines 132 to 137 in 72da2c7

	* @param detailLevel -- For Future -- Perhaps faster way to just return true/false without
	* processing everything and returning a report. For big data sets, perhaps run samples
	* looking for invalids? Not sure how much faster and/or what the break-even would be
	* @return Tuple of Dataframe report and final boolean of whether all rules were passed
	*/
	def validate(detailLevel: Int = 1): (DataFrame, Boolean) = {

dataframe-rules-engine/src/main/scala/com/databricks/labs/validation/Validator.scala

Lines 148 to 149 in 72da2c7

	val first = collect_set(rule.inputColumn).alias(rule.ruleName)
	val results = Seq(invalid.cast(LongType).alias("Invalid_Count"), failed)