Fast follows on new task/note behaviors (#6477)

In this PR, I'm fixing two issues that we have faced:
- computing a rich text first line in case of the first block content is
not a text
- migrating existing timelineActivities tied to tasks / notes to
linked-tasks / linked-notes during migration command

packages/twenty-server/src/database/commands/upgrade-version/0-23/0-23-update-activities.command.ts

@@ -165,11 +165,25 @@ export class UpdateActivitiesCommand extends CommandRunner {
 
           await timelineActivityRepository.update(
             {
+              name: 'note.created',
               linkedObjectMetadataId: activityObjectMetadataId,
               linkedRecordId: activity.id,
             },
             {
               linkedObjectMetadataId: noteObjectMetadataId,
+              name: 'linked-note.created',
+            },
+          );
+
+          await timelineActivityRepository.update(
+            {
+              name: 'note.updated',
+              linkedObjectMetadataId: activityObjectMetadataId,
+              linkedRecordId: activity.id,
+            },
+            {
+              linkedObjectMetadataId: noteObjectMetadataId,
+              name: 'linked-note.updated',
             },
           );
 
@@ -214,11 +228,25 @@ export class UpdateActivitiesCommand extends CommandRunner {
 
           await timelineActivityRepository.update(
             {
+              name: 'task.created',
               linkedObjectMetadataId: activityObjectMetadataId,
               linkedRecordId: activity.id,
             },
             {
               linkedObjectMetadataId: taskObjectMetadataId,
+              name: 'linked-task.created',
+            },
+          );
+
+          await timelineActivityRepository.update(
+            {
+              name: 'task.updated',
+              linkedObjectMetadataId: activityObjectMetadataId,
+              linkedRecordId: activity.id,
+            },
+            {
+              linkedObjectMetadataId: taskObjectMetadataId,
+              name: 'linked-task.updated',
             },
           );
           await attachmentRepository.update(