Add Webhook Endpoint for Activity Updates from Stakwork

[aliraza556]

Describe your changes

Issue ticket number and link

-https://community.sphinx.chat/p/csb4dj2tu2rqjmn086qg/assigned/3653/0

Demo:

https://www.loom.com/share/bb27beffb2cf4edab5e9bd60e876c22d

Show video evidence of activity creation using no thread ID (this would be a new activity).

Show video evidence of activity creation with an existing thread ID included (this would be a response to a previous activity).

DB:

Unit Test:

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist before requesting a review

• I have performed a self-review of my code
• I have tested on Chrome and Firefox
• I have tested on a mobile device
• I have provided a screenshot or recording of changes in my PR if there were updates to the frontend

[aliraza556]

@humansinstitute Please review this PR.