…use the spec has changed

- Add check of constraint AASd-014 for Entity, see https://rwth-iat.github.io/aas-specs/AASiD/AASiD_1_Metamodel/index.html#Entity
- Add check of constraint AASd-131 for AssetInformation, see https://rwth-iat.github.io/aas-specs/AASiD/AASiD_1_Metamodel/index.html#AssetInformation
- Refactor de-/serialization of Entity
- Refactor deserialization of AssetInformation because of check of constraint AASd-131

Add function for checking `Iterable[SpecificAssetId]`

- Add globalAssetId for all `ÀssetInformation`
- Fix Entity.specificAssetIds in test files

- Use getter/setter decorators for global_asset_id
- Refactor `Entity.__init__`: use setter for `entity_type` and remove `_validate_asset_ids_for_entity_type()` from init because it will be called in `entity_type` setter
- Add return type to some init funcs of abstract classes to calm down MyPy

The default inherited `clear()` implementation repeatedly deletes the
last item of the list until the list is empty. If the last item can be
deleted successfully, but an item in front of it that will be deleted
later cannot, this makes `clear()` non-atomic.

Thus, the `clear()` method is now overriden in an atomic way.
Furthermore, the ConstrainedList atomicity test is fixed to correctly
test for this as well.

This decorator silently overrides the `global_asset_id` property,
resulting in the constraints not being checked properly.

… to setter

This only needs to be checked if the `global_asset_id` changes.

`_validate_asset_ids_for_entity_type()` only needs to know whether there
are `specific_asset_ids` or not. This can be represented by a boolean,
allowing the delete hook of the `ConstrainedList` to make use of this
function as well.

Similar to `submodel.Entity`, this is done to reduce duplicate code.

…ecific_asset_id`

Since `__setitem__` can be used to clear the list as well (e.g.
`list[:] = ()`), the constraints need to be verified in this case as
well.

The attributes need to be assigned bypassing the setters because the
setters try to access attributes that haven't been set yet for
constraint validation. Only `global_asset_id` is set via the setter
as a final constraint validation, and because `global_asset_id` is
also constrained via a string constraint.

…ty}.specific_asset_id`

This prevents setting the attributes without verification of the constraints.

…to `Entity`

This adds an `item_add_hook` to the `specific_asset_id`
`ConstrainedList`, which is called whenever a new item is added to the
list. This is necessary because a co-managed `Entity` is not allowed to
have specific asset ids, so it shouldn't be possible to add any in this
case.

…et_id` type hints

improve `AssetInformation` and `Entity` constraint validation + add tests

- Refactor hook funcs param names
- Set all private attributes, bypassing setters.
- Place setting of `Entity._global_asset_id` ahead of `Entity._specific_asset_id` to set item_add_hook directly in the ConstrainedList initialization
- Rename `Entity._validate_asset_ids_for_entity_type` to `Entity._validate_asset_ids`
- Place check of `global_asset_id` value into `_validate_asset_ids`
- Run `_validate_asset_ids` at the end of init

- Bundle check methods together at the end of classes
- Extract validation of `global_asset_id` to `_validate_asset_ids()`
- Rename `Entity._validate_asset_ids()` to `_validate_aasd_014` and `AssetInformation._validate_asset_ids()` to `_validate_aasd_131`, as the methods only validate these constraints and not all asset ids