MDL-43738 behat: Updating step definitions

The following used steps where replaced by the ones
added in this issue:
- I fill the moodle form with
- I fill in with
- I select from
- I select radio button
- I check
- I uncheck
- the field should match
MDL-43738 behat: Removing test for deprecated steps

- the ASD checkbox should be checked
- the ASD checkbox should not be checked
MDL-43738 behat: More info about how to get/set fields