[Feature Request]: Add generate forever/cancel generate forever options when right-clicking generate button in deforum

### Is there an existing issue for this?

- [X] I have searched the existing issues and checked the recent builds/commits

### What would your feature do ?

If possible could the "generate forever/cancel generate forever" options found in txt2img of webui when right-clicking the generate button be added to the deforum generate button to allow for automatic continuous generations?

### Proposed workflow

1. Right-click the generate button to have pop-up box show the generate forever/cancel generate forever options
2. Selecting "generate forever" will continuously generate animations automatically one after the other until cancelled without need to manually hit generate each time
3. Selecting "cancel generate forever" would stop the automatic continuous generation and go back to manual mode

### Additional information


### Are you going to help adding it?

Did what I could, see my modified webui javascript>contextMenus.js code below to add generate forever/cancel generate forever functionality to deforum

Start with the modified webui JavaScript contextMenus.js code mentioned in the issue and trace how the Deforum generate button is wired. Compare its behavior with the existing txt2img generate-forever menu; done means right-clicking Deforum's button exposes generate-forever and cancel options, continuously runs animations until cancelled, and preserves manual generation afterward.

Written by the indexing model from the issue text.