Allow reporting ContentNotAvailableException

[Stypox]

What is it?

• Bugfix (user facing)
• Feature (user facing) ⚠️ Your PR must target the refactor branch
• Codebase improvement (dev facing)
• Meta improvement to the project (dev facing)

Description of the changes in your PR

Followup to #12603

I don't like the solution in this PR but it will have to do for now. The proper solution, in my opinion, would be to distinguish between "content not available because it is blocked/deleted/paid/inexistent" and "content not available because we could not extract it" at the extractor level, but I think we need to discuss a bit more among the team first. For now the distinction is done in the app by filtering all possible exception subtypes, and showing the "Report" and "Retry" buttons only

Fixes the following issue(s)

• Fixes Missing "Report" button in error panel #13130

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR. You can find more info and a video demonstration on this wiki page.

Due diligence

• I read the contribution guidelines.
• The proposed changes follow the AI policy.
• I tested the changes using an emulator or a physical device.