CompareStoredQueries: switch to use Diff
Big refactoring of CompareStoredQueries and
CompareStoredQueriesHideMatchingRows delegating all matching work to DataTablesDiff.
Some exception reporting may still need refining.
@Override for doTable in CompareStoredQueries*
Extract loadRowStructure to separate source file
refactor loadRowStructure
Extract some Parse matchers in separate classes
 - Recursive IsParseThat matcher
 - IsParseWithBody
 - IsParseWithTag
 - Refactor FitFixtureReportingSystemTest
unit tests: NumRowsWithDescription in own src file
refactor unit tests: NumCellsThat to own src file
unit tests: refactor IsParseThat
FitFixtureReportingSystemTest: clean unused imports
CompareStoredQueries: add curly brackets on if
Remove MatchableObject
Revert MatchableObject from MatchableDataTable
DataCellDiff: exception cases handling
Emit null vs null or raised exceptions as EXCEPTION events
Refine DataCellDiffTest: assertions via assertThat
also removed unused imports
DataRowDiff + test - unused imports cleanup
DataTableDiff: rm table1 attrib, rm listener c-tor
 - table attribute removed to better align with current 2-arg diff convention
 - passing listener via c-tor is not so helpful: inherited addListener should be
   good enough
Add MatchingMaskBuilder
Extract buildMatchingMask to separate class
Refactor DataTableDiff: use MatchingMaskBuilder
DataTableDiffTest: common objects as attributes
Move common objects as pre-configured class attributes
Mv setup helpers from DataTableDiffTest to DiffTestUtils