fix(commons): deduplicate logic to keep behavior consistent [#9][#11]

[rmlibre]

Is this a new bug in aiootp?

• This affects a supported version of aiootp
• This isn't a security vulnerability or issue
• I've searched the existing issues, & I couldn't find one for this bug

Current Behavior

Behavior which is specified by subclasses of Slots in their __setitem__ methods can be bypassed when providing values to the default __init__.

Expected Behavior

The same behavior which is specified in the __setitem__ by a subclass of Slots is applied when using all attribute & value setting interfaces.

Steps To Reproduce

1. With this config:

from aiootp.commons import typed_slots

class Example(typed_slots.FrozenTypedSlots):
    __slots__ = ("attr",)
    slots_types = dict(attr=int)

2. Run:

e = Example(attr="not an int")
# no error

e = Example(attr=2)
e.__init__(attr=4)
# no error, even though frozen

3. See error:

There was no error, but that's the issue.

Relevant log output

No response

Environment

- OS: Ubuntu 20.04
- Python: 3.8.10
- aiootp: 0.23.9

Additional Context

This issue is indicative of a lack of consistency, where logic is duplicated in various methods. Perhaps relying on super() for shared functionalities would be a viable mitigation. This is related to #9 & #11.

[rmlibre]

Resolved by (26e0026) from [#15]