feat: adds extra cache key components support

[pySilver]

I was surprised to find my own ticket here haha :)

This feature allows to bind our memoized functions with external state. Extra argument can be anything json-serializable or even callable.

@cache_memoize(60, extra=('foo', obj.pk, foo.last_updated_at))
def foo(*args, **kwargs):
    return 42

@cache_memoize(100, extra={"version": 2})
def callmeonce(arg1):
    print(arg1)

@cache_memoize(100, extra=100500)
def callmeonce(arg1):
    print(arg1)

@cache_memoize(100, extra=lambda user: user.is_staff)
def callmeonce(user):
    print(arg1)

Originally requested at #49 (solves #35 )

[pySilver]

Can we merge it?

[pySilver]

@peterbe :) kind reminder about PR. It contains tests and it is fully BC.

[peterbe]

@peterbe :) kind reminder about PR. It contains tests and it is fully BC.

Sure! Can you merge in latest main and that should start the CI suites.

[pySilver]

@peterbe Oh I've missed your reply. I've just synced master branch with this PR