Port behat changes to 4.0

[PhMemmel]

This PR cherrypicks the behat refactoring part of f9c525c and adds it to the master (4.0 compatible) branch.

Compatibility for flexsections and grid format is being left out as there both of these plugins do not seem to be compatible with moodle 4.0 yet.

[Syxton]

@PhMemmel I am running behat tests with all the 3rd party formats we have every accepted (flexsections, tiles, grid, topcoll, onetopic). It is a mess right now. I will make sure I have the latest of each and try again tomorrow.

[PhMemmel]

Thank you. Will at some point hopefully get my behat setup working. No idea what causes trouble there...

Should we consider splitting up the behat tests so we have a separate file for each course format?

[Syxton]

@PhMemmel I am getting ready to push a split up set of behat tests. Here are my current testing results for all course formats we have been dealing with. With core formats not using indent, I have moved the indent tests to each format set.

core passes all tests pass (1 skip is expected to test the "format is not installed" test)
topcoll latest passes all tests and should be supported.
grid needs updated to remove deprecated functions and implement indent, but our tests for it are probably correct. With all warnings hidden, mass actions will work except for indent. Could be supported.
tiles needs updated to remove deprecated functions and implement indent, but our tests for it are probably correct. With all warnings hidden, mass actions will work except for indent. Could be supported.
onetopic needs updated to remove deprecated functions and implement indent, but our tests for it are probably correct. With all warnings hidden, mass actions will work except for indent. Could be supported.
flexsections needs updated to remove deprecated functions and implement indent, but our tests for it are probably correct. In its current state, it breaks Moodle severely and should not be supported yet.