Review / improve support for dot-delimited field paths in `Store` + data package

[febbraiod]

When using a dot separated field path to specify a field on a column, it must be specified using the string form of the field:

field: 'levelOne.nestedField'

Using a a config for a typed store field as a dot-separated path causes the value in the column to be null:

field: {name: 'levelOne.nestedField', type: FieldType.NUMBER}