Group multiple updates for the same ticket in digest emails

In the bulk update summary emails, tickets that received multiple actions (e.g., a status change plus a new comment) appear as duplicate entries in the list. This clutters the notification email with redundant lines for the same issue ID.

Instead of creating multiple bullet points for a single issue, the notification generator should aggregate all recent events into a single entry per ticket, reflecting its latest state and actions taken.

Rationale / Why it's needed:

Reduces Email Clutter: Keeps digest emails concise and easy to skim.
Clearer Context: Shows the final status and combined activity for a ticket at a glance without duplicate rows.

Suggested Implementation:

Deduplicate ticket entries in the email template renderer by grouping events by Ticket ID.
Format consolidated entries to display the latest status alongside performed actions (e.g., [Done] New comment on FT-60: [Title]).

Rationale / Why it's needed:

Reduces Email Clutter: Keeps digest emails concise and easy to skim.
Clearer Context: Shows the final status and combined activity for a ticket at a glance without duplicate rows.

Suggested Implementation:

Deduplicate ticket entries in the email template renderer by grouping events by Ticket ID.
Format consolidated entries to display the latest status alongside performed actions (e.g., [Done] New comment on FT-60: [Title]).