feat: add ability to delete gray messages (WPB-5840)

[thisisamir98]

WPB-5840 [Web] Ability to delete grey messages (messages that are not sent)

Description

This pull request addresses the implementation of a crucial feature - the ability for users to delete messages that were never sent, commonly referred to as "grey messages." The feature covers regular text messages, self-deleting messages, as well as pictures/assets that haven't been sent.

The implementation includes modifications to the message handling logic to recognize and handle unsent messages appropriately. The "Delete" option in the context menu now triggers the removal of the selected unsent message from both the user interface and the local database.

Screenshots/Screencast (for UI changes)

Checklist

• PR has been self reviewed by the author;
• Hard-to-understand areas of the code have been commented;
• If it is a core feature, unit tests have been added;

[codecov]

Codecov Report

Merging #16375 (4ecfcf6) into dev (656a26c) will decrease coverage by 0.01%.
Report is 19 commits behind head on dev.
The diff coverage is 33.33%.

❗ Current head 4ecfcf6 differs from pull request most recent head e4e2f84. Consider uploading reports for the commit e4e2f84 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##              dev   #16375      +/-   ##
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- Coverage   45.45%   45.44%   -0.01%     
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  Files         733      733              
  Lines       23721    23723       +2     
  Branches     5397     5398       +1     
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  Hits        10782    10782              
- Misses      11574    11575       +1     
- Partials     1365     1366       +1     

[PatrykBuniX]

@thisisamir98 it looks good to me, how about adding a simple test scenario that covers this one case? We can add it to deleteMessageForEveryone tests.

[PatrykBuniX]

Well done!