Feat: push up helpers

[z3z1ma]

This is just a donation of some helper classes. Feel free to hack away.
I can also share how I have personally used them to simplify quite a few APIs.

[alex-harness]

Example complete pipeline

import dlt

from continuous_data_flow.sdk.authenticators import BearerTokenAuthenticator
from continuous_data_flow.sdk.paginators import JSONPathPaginator
from continuous_data_flow.sdk.rest import RestAPIEndpoint, RestAPIEndpointFactory


class QualifiedEndpoint(RestAPIEndpoint[str]):
    def get_request_params(self, next_page_token):
        params = {"limit": 2000}
        if next_page_token:
            params["starting_after"] = next_page_token
        return params


class QualifiedAPI(
    RestAPIEndpointFactory[QualifiedEndpoint, JSONPathPaginator, BearerTokenAuthenticator]
):
    base_url = "https://api.qualified.com/v1/"
    endpoint_klass = QualifiedEndpoint
    default_paginator = JSONPathPaginator(jsonpath="$.meta.end_cursor")
    records_jsonpath = "$.data[*]"


@dlt.source
def qualified(api_token: str = dlt.secrets.value):
    """Qualified source for DLT"""
    api = QualifiedAPI(authenticator=BearerTokenAuthenticator(token=api_token))
    return (
        dlt.resource(
            iter(api.endpoint_factory(endpoint)),
            name=endpoint,
            write_disposition="replace",
            primary_key="id",
        )
        for endpoint in ("rep_conversations", "bot_conversations")
    )

[rudolfix]

heh this is so good :) definitely should go into core library @z3z1ma thx! @steinitzu pls take a look