Fix merged ticket responses not being added to parent ticket

[RomainLvr]

Q	A
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets	!32514

Description

When merging a Child ticket C into a Parent ticket P, the following issues were observed:

1. Merging Process:

   • The content of ticket C is successfully added to ticket P.
   • The status of ticket C is set to "deleted".

2. Post-Merge Responses:

   • Responses posted to ticket C (now merged and deleted) are correctly added and visible.
   • Responses sent to ticket C are not added to ticket P. Instead, they remain visible in ticket C, which is no longer tracked due to its deleted status. However, they should be present in the parent ticket.

Resolution

To solve this problem, a post-add response step has been added, which detects parent tickets (if the ticket in question is a merged ticket) and then duplicates the tracking in the parent ticket.

[trasher]

Please add tests

[cedric-anne]

Seems OK (apart the missing sanitization), but I think it should target the main branch.

[RomainLvr]

@cedric-anne
I noticed that the sanitize() function is deprecated. I then came across this commit 440adc3. Is it necessary to sanitize the input?

[cedric-anne]

@cedric-anne I noticed that the sanitize() function is deprecated. I then came across this commit 440adc3. Is it necessary to sanitize the input?

On main branch, it is not necessary to sanitize the input anymore. You can revert this change.

[trasher]

Please rebase to solve conflicts