Format tests with on_days and/or before/after_time as budgets

[tijlleenders]

Is your feature request related to a problem? Please describe.
Anything that has an on_day filter and/or before/after_time is a budget - since that feature is not available for 'simple' goals.

Describe the solution you'd like

• Go through all tests in tests/jsons/validated/ and tests/jsons/stable.bak and transform the input.json to a budget goal for any goal that has an on_day filter.
• Also transform the input.json from a map of goals to a list of goals and use camelCase.
• Update impossible tasks format to empty string or other expectation in new format

Describe alternatives you've considered
Allow on_day on 'simple' goals. This goes back on frontend UX decision to split budgets from goals for easier input interface. Budgets are done once - or at least infrequently. Goals can make use of a budget by being a sub-goal of a budget.

Additional context
An example of a input.json that needs to be transformed is tests/jsons/stable.bak/before-7/input.json