Similar logic to `.explain()`, create a function to show unneeded options or missing options

[richardhathaway-8451]

Similar to explain create a function to show unneeded options or missing options. For example, consider a large application with many options and datasets, one of which is below.

@dataset
def foo(
    region = Option("APPLICATION.REGION", "North")
):
    ...

A user may mistakenly add an option to their options dictionary with a small typo, such as {"APPLICATION": {"REGIONS": "South"}}, mistaking "REGION" for "REGIONS". The application would still run without error because the option has a default value, but it would run with a wrong value, and the user might not catch the mistake.

A function that would show the user what options are missing from the config and what options are not used (because they are entered incorrectly) would help validate options dictionaries. For example:

options = {"APPLICATION": {"REGIONS": "South"}}
validate(foo, options)

# Missing options: 'APPLICATION.REGION'
# Unused options: 'APPLICATION.REGIONS'

[jjmarchewitz]

@richardhathaway-8451 I can see the use case for unused options, but I'm not sure about missing ones. Wouldn't missing options cause KeyNotFoundErrors to be thrown when they are accessed? This seems like the correct behavior to me, but I am interested to hear if you have a use case/reasoning for wanting a dedicated function

[jjmarchewitz]

Maybe the functionality for performing diffs could live in confectioner, there could be a function diff(a: Options, b: Options) -> Options that essentially returns a - b. Users of Labrea would call it like so

@dataset
def foo(a = Option('A')):
   ...

options = {'A': 1, 'B': 2}
used_options = foo.evaluate_options(options)
unused_options = diff(options, used_options)

print(unused_options)
>>> {'B': 2}

or there could be a concrete method in the base class

class Evaluatable(ABC):

    # other methods here...

    def unused_options(options: Options) -> Options:
        used_options = self.evaluate_options(options)
        return diff(options, used_options)