Table read option to include null values

[Yuqi-Du]

For table read, we made the decision of not returning null column values.
So we need to have an option of let user override the default behavior.

This nullOption is originally included in #1633, @amorton wants to think on naming stuff, so separate out as an issue,

related issue
#1571

[amorton]

lets call the option enableVerboseData , the problem is this will be default to false for tables or true for collections. Does not matter what the flag is called, it will be diff for the two :(

the other choice we had was disableSparseData.

Lets get the feature ready and then see what the command looks like, the hard part will be how we make this make sense for tables and collections.

[amorton]

discussion - go with enableVerboseData as the name, defaults to false, and if set to true and it is a Collection throw an error. For collections we assume the user put NULLS into the document on purpose. Can revisit later.