[BUG]: Investigate Schedule Interaction With Validation & Test Data

[nmichlo]

Describe the bug
Schedules may unintentionally be affected by the use of validation and test data enabled in release v0.3.4 5695747

• These steps might increment trainer.global_step

Conversely validation and test steps will use the current value of the schedule.

• This should probably instead be the original value in the config

This issue is in response to the fixes introduced in #22

Expected behaviour
I am not sure what the expected behaviour should be in some cases. Further discussion may be required.

• The framework may need to check if a schedule wants its value to be used or a default value for the validation and test steps, this functionality should possibly be configurable.