[IMP] utm, crm: add lead/opportunity stats on campaign

PURPOSE

This commit removes the mass_mailing.campaign model. Instead of having a fully
fledged model, we will simply inherit utm.campaign. We will also add relevant
statistics on utm campaign model in order to use it in various applications.

SPECIFICATIONS

This commit adds leads/generated statistics in the kanban and
the form view of the utm campaign.

Kanban and form views will now display the number of leads and
opportunities generated with the campaign

TaskID: 2002029
PR: #34452

0 files changed, 0 insertions, 0 deletions