Add analysis of schema structure decomposition of field keys and subtypes

[ivbeg]

Flat table datasets (CSV) files, database tables, and sometimes objects with nested objects ofter include elements that could be grouped.

For example CSV file Zaara_D.csv
includes following fields: title, text, date, place, placeURL, placeLocation, placeType, reviewScore, avgScore

We could find that prefix 'place' is a subtype identifier. It could be decomposed as
place:

• Name
• Location
• URL
• Type

And postfix Score identifies value type, whether integer or float.

Most data tables use case change or "_" symbol as dividers. Very rarely is the '-' symbol also used.

Detection of field groups and decomposition of field names could help with:

• additional rules to detect semantic data types
• automatic context identification

Add group detection to the final report as field_group property.