feat: Error message when the access to the user gallery is denied (iOS only)

[g123k]

Hi everyone,

We currently have the following issue:

• The app asks the user to select a source (camera/gallery)
• He/she selects the gallery and denied the popup from iOS
• The next time he/she clicks on the gallery, nothing will happen in the app

We now support this case by explaining the problem and redirecting to the settings.
It's also an iOS-only issue.

It will fix #4462

[codecov-commenter]

Codecov Report

Merging #4464 (33fac11) into develop (520b90c) will decrease coverage by 0.02%.
The diff coverage is 0.00%.

@@             Coverage Diff             @@
##           develop    #4464      +/-   ##
===========================================
- Coverage    10.36%   10.34%   -0.02%     
===========================================
  Files          296      296              
  Lines        15241    15267      +26     
===========================================
  Hits          1579     1579              
- Misses       13662    13688      +26     

Files Changed	Coverage Δ
...p/lib/generic_lib/dialogs/smooth_alert_dialog.dart	67.85% <0.00%> (-0.35%)	⬇️
packages/smooth_app/lib/pages/image_crop_page.dart	0.79% <0.00%> (-0.20%)	⬇️

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[github-actions]

You can test this PR on: Android