Change label for `hours_worked`

[MaxGhenis]

To Hours worked per week so it's more descriptive in PolicyEngine:

https://github.com/PolicyEngine/openfisca-uk/blob/3a2c3516220c4ed171d60bbcaeeb4e440bb59272/openfisca_uk/variables/finance/income.py#L146

[nikhilwoodruff]

Look at that old interface!

[MaxGhenis]

Haha indeed. Should we change the definition_period to week?

policyengine-uk/policyengine_uk/variables/household/income/income.py

Lines 61 to 66 in a8a2c1c

	class hours_worked(Variable):
	value_type = float
	entity = Person
	label = "Total amount of hours worked by this person"
	definition_period = YEAR
	unit = "hour"

[anth-volk]

Is there any potential that this would somehow be cast into a year-long value at some point, whether in calculation or in display on the front end?