cleanup: move config to python code

[franciscobmacedo]

removed dynamic configuration loader from yaml file (ssda903/fixtures/config/standard-v1.yaml) and moved it into python code.
Now, age brackets, placement categories and costs are all written in python, so everything is detectable by your IDE.

Also changed all the dataframe values to just have the "label" of the placement category or age bracket - that's the human readable value, which is easy to display in the web but still accessible programmatically, with the enum values.

@amynickolls just be aware that everytime you need to filter something use it like this:

data.loc[
    data.placement_type_before == PlacementCategories.NOT_IN_CARE.value.label
]

Because:

• PlacementCategories is an enum
• PlacementCategories.NOT_IN_CARE is an enum member
• PlacementCategories.NOT_IN_CARE.name is actually "NOT_IN_CARE", the enum member name
• and PlacementCategories.NOT_IN_CARE.value is an instance of the dataclass PlacementCategory with it's label "Not in care"
• PlacementCategories.NOT_IN_CARE.value.label is the name of this PlacementCategory instance, so in this case "Not in care"

There's examples in the docstrings of PlacementCategories and AgeBrackets.

I hope now it's more clear!!

[amynickolls]

No comments - thanks for the detailed comments in the code!