Catch up to JS client

[fnesveda]

There were a few changes to the JS client in the past that were not propagated to the Python client, we need to catch up.

We need to add these features:

• actor run env vars client (feat: Add clients for actor env vars apify-client-js#202)
• x-apify-workflow-key header (feat: Adding x-apify-workflow-key header apify-client-js#212)
• schema parameter in get_or_create methods for key-value store & dataset (feat: Add schema parameter to getOrCreate for kvs, dataset apify-client-js#233)
• origin param for last actor/task run endpoints (feat: origin param added for last actor/task run endpoints apify-client-js#248)
• view parameter in dataset items methods (feat: Add support for the view parameter in dataset items client apify-client-js#226)
• flatten parameter in dataset items methods (feat: Add flatten param to Dataset items listing apify-client-js#264)
• optional title field in task, schedule, key-value store, dataset, and request queue client methods (feat: Add optional title field to task, schedule, key-value store, dataset, and request queue apify-client-js#271)