Rename CollectionStatistics to FieldStats and TermStatistics to TermStats.

[vsop-479]

No description provided.

[jainankitk]

Without any context around why it was called CollectionStatistics, this change makes sense to me. Although, I am wondering if we should rename the corresponding methods and parameters as well to be inline with this change?

[vsop-479]

Thanks @jainankitk ! I will do it.

[rmuir]

I don't remember the reasoning behind the name, but I think FieldStatistics is better.

One thing to consider, we also have NumericFieldStats class. Maybe we want to think about more consistency and shorter names? e.g. FieldStats/TermStats/NumericFieldStats ?

Would just not be great to have to rename it yet again.

[vsop-479]

One thing to consider, we also have NumericFieldStats class. Maybe we want to think about more consistency and shorter names? e.g. FieldStats/TermStats/NumericFieldStats ?

Makes sense, I will rename FieldStatistics to FieldStats, and TermStatistics to TermStats.

[vsop-479]

I also added an entry in MEGRATE.md.