Add blocked channels to search, trending, and recommendations

[mstudio005]

What is it?

• Feature (user facing)

Description of the changes in your PR

• Added a Room database table to store blocked channels with their name and URL
• Added a Blocked Channels screen under Settings → Content
• Added a Block channel option in the video long-press menu with an undo snackbar
• Filtered blocked channels from search results, trending, and related videos
• Fixed a crash on the Blocked Channels settings screen on Android 16
• Fixed a bug where filtering tried to modify immutable lists

Before/After Screenshots/Screen Record

Fixes the following issue(s)

• Fixes Block Channels #12647
• Fixes Blacklist videos, channels and keywords  #1815

Relies on the following changes

• None

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.

Due diligence

• I read the contribution guidelines
• The proposed changes follow the AI policy
• I tested the changes using a physical device (Samsung Galaxy Tab A9+ 5G, Android 16)

[RobertKillick]

I have been increasingly wanting this feature to exclude the vast amount of AI slop out there. I have vibe coded what looks to mostly be a duplicate of this work (the irony isn't lost on me).

It is passing tests, I have also validated back up and restore of the DB is working.
I have only been test driving it for a short time on an S26 Ultra but it seems work well. I planed to also test it on number of other old phones I have until i saw this.

Given the last commit was a while ago are people trying to push this work forward? Opening another PR for what I have isn't going help as this is still open

[TobiGr]

Please take look at the failing DB migrations and add tests for the new feature. YOu might want to rebase your PR