Migrate from a global config __future__ to control behaviour to plugin
specific options to decide on whether to take the param order from yaml
when using the trigger-parameterized-builds plugin or when plugins are
making use of it as well.
Adjust the config retrieval to support a default value to simplify
logic around ensuring the behaviour matches 'true' by default.
Remove some redundant logic in helper module handling a default value
lookup and add some additional conf files to continue having some tests
using the old behaviour.
Remove old conf files setting the __futures__.param_order_from_yaml to
true as this is now the default under the correct plugin setting.
Change-Id: Ibd5f549b6d626bacaaa4221015a70aaf03626b00
Darragh Bailey