Channel category page + video thumbnail resolution bump

[mykhailodanilenko]

🚀 Description

This PR adds a page for channel category; increases videos number in lists that are extensible to 16 from 12; uses previews instead of thumbnails in video grids (mentioned in #147); See deployed at https://mykhailodanilenko.github.io/web-client/

📄 Motivation and Context

closes #146, #147

🧪 How Has This Been Tested?

Web and mobile

📷 Screenshots (if appropriate)

📦 Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

✅ Checklist (copied from README)

• [x] Squash your changes into a single clear and thoroughly descriptive commit, split changes into multiple commits only when it contributes to readability
• [x] Reference the GitHub issue that you are contributing on in your commit title or body
• [x] Sign your commits, as this is required by the automated GitHub PR checks
• [x] Ensure that the changes adhere to the project code style and formatting rules by running npx eslint . and npx prettier --check ../ from the ./OwnTube.tv/ directory (without errors/warnings)
• [x] Include links and illustrations in your pull request to make it easy to review
• [x] Request a review by @mykhailodanilenko, @ar9708 and @mblomdahl

[mblomdahl]

Thank you @mykhailodanilenko! Looks great. I was trying to find the good old build-info thing from #20 and #84, to see what version was deployed. But I could not find it. Is it gone? If so, please add a ticket to re-enable this functionality.