Apply the five-year-forward check for all reforms

Currently some reforms only apply if they're active in the default simulation year, which is currently 2024. This caused #4909, for example.

We should add checks like I'm doing in #4911 to all reforms, to ensure that they apply as intended if activated after 2024.

Start by reading issue #4911 and the example in #4909 to understand the five-year-forward check. Then locate the reforms that currently depend on the default simulation year and apply the same check consistently; done means reforms activated after 2024 behave as intended across the affected cases.

Written by the indexing model from the issue text.