VoIP users can now open CRM leads linked to a contact directly from the softphone. This helps sales teams move from a call to the related opportunity information faster, using the same experience already available for recruitment applicants.

This commit adds a button that connects the contacts to its leads via the VoIP module. It uses the same logic as "Applicant" button introduced before.

Task-4855484

Community: https://github.com/odoo/odoo/pull/214031