ui.table configure totals table aggregations

[dsmmcken]

We would want to map to ui state in the aggregations side bar

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The current groovy API:

• boolean field for showTotalsByDefault (defaults to false)
• boolean field for showGrandTotalsByDefault (defaults to false)
• has a default operation, to be applied to any unspecified column (defaults to SUM)
• has a map from column name to set of agg operations, so a column can be specified with the operations that should be applied to it
• has a map from column name plus agg operation to format string, to format the various totals values

Supported operations:

• Count
• Min - comparable columns only
• Max - comparable columns only
• Sum - numeric columns only
• AbsSum - numeric columns only
• Var - numeric columns only
• Avg - numeric columns only
• Std - numeric columns only
• First
• Last
• Group (mentioned for completeness, but explicitly not supported)
• CountDistinct
• Distinct
• Unique
• Skip