[backend] now also send stream message in digest notifications (#8685)

[JeremyCloarec]

Proposed changes

• now also send stream message in digest notifications

Related issues

• Spamming user when modifying a report assigned to someone #8685

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality
• I wrote test cases for the relevant uses case (coverage and e2e)
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality

Further comments

[codecov]

Codecov Report

Attention: Patch coverage is 4.00000% with 24 lines in your changes missing coverage. Please review.

Project coverage is 65.67%. Comparing base (1fe0353) to head (c9395ce).
Report is 8 commits behind head on release/current.

Files with missing lines	Patch %	Lines
...rm/opencti-graphql/src/manager/publisherManager.ts	4.34%	22 Missing ⚠️
...opencti-graphql/src/manager/notificationManager.ts	0.00%	2 Missing ⚠️

Additional details and impacted files

@@                 Coverage Diff                 @@
##           release/current   #11004      +/-   ##
===================================================
+ Coverage            65.64%   65.67%   +0.03%     
===================================================
  Files                  680      680              
  Lines                67304    67320      +16     
  Branches              7426     7435       +9     
===================================================
+ Hits                 44182    44213      +31     
+ Misses               23122    23107      -15     

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[lndrtrbn]

as AuthUser is not needed

[lndrtrbn]

not a fan neither of as string to bypass the fact that TypeScript is telling that user_id can be undefined
it would be better to trust TypeScript and use .get(user_id ?? '') to be sure to pass a string as argument

[JeremyCloarec]

I'll improve it yes you're right, this was copy pasted and refactored from what was done in processLiveNotificationEvent before