feature: refactor skill_x_api and add image generation

[shihao-guo]

Description

Refactor skill_x_api.py to use composio for posting tweets with optional image_urls. image upload to twitter_media is handled inside of skill_x_api.py.

Refactor activity_post_recent_memory_tweet to use the new x api skill.
Refactor activity_post_a_tweet to use the new x api skill, plus a setting to generate an image for the tweet.

Fixes # (issue)

Type of Change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration.

• Tested live with a tweet that generated image.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

Screenshots (if applicable):

Add any relevant screenshots here.

Additional Notes:

image generation is a lot more costly than chat completion. Make sure to turn it off, or set a probability using random number to generate image occasionally.