Implement Tab getLocalStorage/setLocalStorage

[nathanfallet]

Based on Zendriver's get_local_storage/set_local_storage, reimplement it in kdriver:

class Tab:

    async def get_local_storage(self):
        """
        get local storage items as dict of strings (careful!, proper deserialization needs to be done if needed)

        :return:
        :rtype:
        """
        if self.target is None or not self.target.url:
            await self.wait()

        # there must be a better way...
        origin = "/".join(self.url.split("/", 3)[:-1])

        items = await self.send(
            cdp.dom_storage.get_dom_storage_items(
                cdp.dom_storage.StorageId(is_local_storage=True, security_origin=origin)
            )
        )
        retval = {}
        for item in items:
            retval[item[0]] = item[1]
        return retval

    async def set_local_storage(self, items: dict):
        """
        set local storage.
        dict items must be strings. simple types will be converted to strings automatically.

        :param items: dict containing {key:str, value:str}
        :type items: dict[str,str]
        :return:
        :rtype:
        """
        if self.target is None or not self.target.url:
            await self.wait()
        # there must be a better way...
        origin = "/".join(self.url.split("/", 3)[:-1])

        await asyncio.gather(
            *[
                self.send(
                    cdp.dom_storage.set_dom_storage_item(
                        storage_id=cdp.dom_storage.StorageId(
                            is_local_storage=True, security_origin=origin
                        ),
                        key=str(key),
                        value=str(val),
                    )
                )
                for key, val in items.items()
            ]
        )