add interval to karate.range() and allow reverse ordering

[edwardsph]

Description

Extends the new karate.range() method to support an optional 3rd argument for the interval. Also allows start and end to be reversed.

  * match list1 == [5, 6, 7, 8, 9, 10]",
  * def list2 = karate.range(5, 10, 2)",
  * match list2 == [5, 7, 9]",
  * def list3 = karate.range(10, 5, 2)",
  * match list3 == [10, 8, 6]"

Docs updated and tests also confirm that an interval of <= 0 will fail to avoid infinite loops.

• Relevant Issues : none
• Type of change :
  • New feature
  • Bug fix for existing feature
  • Code quality improvement
  • Addition or Improvement of tests
  • Addition or Improvement of documentation