[Enhancement] Convert Params Models To Dictionary Before Assigning As Private Attribute In OBBject.

[deeleeramone]

1. Why?:

   • ^^

   • Every process downstream accessing this private attribute converts to a dictionary immediately, so this does the job once instead of repeating in multiple places.

2. What?:

   • obbject._standard_params is now a dictionary.
   • Updated the registry in CLI to reflect the change.
   • Updated openbb-charting init to reflect the change.

3. Impact:

   • This only impacts the charting extension and CLI, however there is no operational change beyond the type conversion.

4. Testing Done:

   • Ran the integration tests.