Fix: Resize image before conversation and save history

[iseabock]

Motivation and Context

There was a bug caused by image upload that didn't allow for history to be saved as well as bug caused by the uploaded image being too large.

Description

Resizing the image then converting to base64 before sending the conversation resolved the issue of image size.

Contribution Checklist

• I have built and tested the code locally and in a deployed app
• For frontend changes, I have pulled the latest code from main, built the frontend, and committed all static files.
• This is a change for all users of this app. No code or asset is specific to my use case or my organization.
• I didn't break any existing functionality 😄