Feature: Make the source resumable when the number of records is defined

[hariso]

Feature description

Currently, if the generator is restarted, it will start generating the data from scratch (e.g. if it's configured to generate 100 records, you restart it after the 30th, then it will start generating from record 1, and the end result will be 130 records).

It would be good to make the generator source resumable, when the number of is defined (since it's also possible to generate records without a limit on the number).

[neovintage]

Not a burning issue but would be nice to be consistent.

[lyuboxa]

I may pick this up, I kind of need this predictability for testing.