Add Options.apply_binds to allow applications to bind before calling user code

In DaVinci a few cases have come up where code ends up looking like:

@configurable
def my_thing(process="MyDefault"):
    ...

Users then use this thing by running:

my_thing(process=options.process)

This gets a bit annoying when code starts being nested with there being multiple layers of

def my_func(process="MyDefault"):
    return my_other_func(process=process)

def my_other_func(process="MyDefault"):
    return my_thing(process=process)

A slightly better option is to make process a keyword only argument and bind:

@configurable
def my_thing(*, process):
    ...

def my_func():
    return my_other_func()

def my_other_func():
    return my_thing()

# Usage looks like
with my_thing.bind(process=options.process):
    my_func() 

This MR expands this slightly by allowing the application-specific Options class to automatically apply binds so the user code doesn't need to use bind. See DaVinci!731 (merged) for an example of this being used.