Add support to provide regex filters on entity queries

Looking into porting some of our code into AYON I noticed how much more complicated the new query functions look using the new API, for example, compare this new implementation of _get_representations on the workfile template: https://github.com/ynput/ayon-core/blob/d8e5734e57c19a740f0fa2c3f4a5984754f68431/client/ayon_core/pipeline/workfile/workfile_template_builder.py#L1436
To how it was in OP before:

def _get_representations(self, placeholder):
        """Prepared query of representations based on load options.

        This function is directly connected to options defined in
        'get_load_plugin_options'.

        Note:
            This returns all representation documents from all versions of
                matching subset. To filter for last version use
                '_reduce_last_version_repre_docs'.

        Args:
            placeholder (PlaceholderItem): Item which should be populated.

        Returns:
            List[Dict[str, Any]]: Representation documents matching filters
                from placeholder data.
        """

        project_name = self.builder.project_name
        current_asset_doc = self.builder.current_asset_doc
        linked_asset_docs = self.builder.linked_asset_docs

        builder_type = placeholder.data["builder_type"]
        if builder_type == "context_asset":
            context_filters = {
                "asset": [current_asset_doc["name"]],
                "subset": [re.compile(placeholder.data["subset"])],
                "hierarchy": [re.compile(placeholder.data["hierarchy"])],
                "representation": [placeholder.data["representation"]],
                "family": [placeholder.data["family"]]
            }

        elif builder_type == "linked_asset":
            asset_regex = re.compile(placeholder.data["asset"])
            linked_asset_names = []
            for asset_doc in linked_asset_docs:
                asset_name = asset_doc["name"]
                if asset_regex.match(asset_name):
                    linked_asset_names.append(asset_name)

            context_filters = {
                "asset": linked_asset_names,
                "subset": [re.compile(placeholder.data["subset"])],
                "hierarchy": [re.compile(placeholder.data["hierarchy"])],
                "representation": [placeholder.data["representation"]],
                "family": [placeholder.data["family"]],
            }

        else:
            context_filters = {
                "asset": [re.compile(placeholder.data["asset"])],
                "subset": [re.compile(placeholder.data["subset"])],
                "hierarchy": [re.compile(placeholder.data["hierarchy"])],
                "representation": [placeholder.data["representation"]],
                "family": [placeholder.data["family"]]
            }

        return list(get_representations(
            project_name,
            context_filters=context_filters
        ))

My worry is not only the fact that the API doesn't provide that same support but the fact that not having that is now forcing the user to provide much more expensive implementations to get to the same result. In the new code you are now having to query ALL products and then filter them rather than doing it directly on the query

Inizia tracciando le nuove funzioni di query delle entità e l’entry point get_representations, quindi confronta il loro comportamento con _get_representations in workfile_template_builder.py dell’esempio AYON Core collegato. Determina come devono essere passati i filtri regex tramite l’API e verifica che il filtraggio avvenga durante la query anziché dopo aver recuperato tutte le entità.