Update project tags type to what is expected/returned by API

[dsciacca]

Description

This PR updates the type hints of the tags property of the Project class to align with what is expected and returned by the Doccano API. This addresses issues around creating, updating, and retrieving Doccano projects that have tags associated. Now that the issue mentioned in #149 is addressed I've found that the DoccanoClient.update_project() method fails to actually update tags when that kwarg is passed. Will open a separate issue for this since you can't actually reproduce the failed update of tags unless this PRs change is part of your local doccano-client

Fixes #149 (Unable to retrieve projects with tags)

Reproduction of issue before fix:
find_project_by_id():

list_projects():

create_project() w/ tags as specified in docs:

create_project() w/ tags as List[Dict[str, str]]:

update_project() w/ tags as specified in docs:

update_project() w/ tags as List[Dict[str, str]]:

Demonstration of successful fix using client created from this branch:
find_project_by_id():

list_projects() (truncated but demonstrates no failure):

create_project():

update_project() here you'll notice tags aren't actually updated but we can tell the call succeeded as the description was updated, this seems to be a separate bug only reproducible once this PRs fix is in place:

NOTE: This work was done as part of my employment at GoGuardian, Inc.

[Hironsan]

Can this problem be fixed by adding and using the following two methods in ProjectRepository? I think this does not change the signature.

def to_domain(response: dict[str, Any]) -> Project:
    """Convert a response to a domain object

    Args:
        response (dict[str, Any]): The response to convert

    Returns:
        Project: The converted project
    """
    response["tags"] = [tag["text"] for tag in response["tags"]]
    return Project.parse_obj(response)


def to_persistent(project: Project) -> dict[str, Any]:
    """Convert a domain object to a persistent object

    Args:
        project (Project): The project to convert

    Returns:
        dict[str, Any]: The converted project
    """
    payload = project.dict()
    payload["tags"] = [{"text": tag} for tag in payload["tags"]]
    return payload

...
    def find_by_id(self, project_id: int) -> Project:
        response = self._client.get(f"projects/{project_id}")
        return to_domain(response.json())

    def create(self, project: Project) -> Project:
        payload = to_persistent(project)
        response = self._client.post("projects", json=payload)
        return to_domain(response.json())

[dsciacca]

@Hironsan good call, this also works and I agree is a better solution. I've reverted my original change and implemented your suggestion w/ some minor changes - i.e. make functions private class methods, remove "id" from the creation dict, if present, and align w/ expectations of unit tests. Please take a look and let me know your thoughts. Thanks!

[Hironsan]

Thanks! Merged.