Add an optional built-in API worker for BeVigil

[postmodern]

Add an optional built-in API worker for BeVigil.

Example Usage

• https://github.com/hueristiq/xurlfind3r/blob/2a369c4b050e6018a36a69146f76ad22fbd3683b/pkg/xurlfind3r/sources/bevigil/bevigil.go#L63-L68