UI: support testing webhook using tryout api

[enudler]

[almogbhl]

Hi, can i take it?

Is the api will be listed in the docs?

[enudler]

hi @almogbhl

the api is called:
/v1/webhooks/{webhook_id}/test
it's in file
docs/openapi3.yaml

assigned to you :)

[almogbhl]

Hi @enudler, which screen would you like the button to be on?

[enudler]

hi @almogbhl
In this screen