Asura Scans: support high quality chapter images

[vetleledaal]

Might be patched in the future, so disabling it by default.

Have not fully considered how caching will be affected by this. User might expect chapters in the cache to be invalidated, but if that is not a concern it should be fine.

Checklist:

• Updated extVersionCode value in build.gradle for individual extensions
• Updated overrideVersionCode or baseVersionCode as needed for all multisrc extensions
• Referenced all related issues in the PR body (e.g. "Closes #xyz")
• Added the isNsfw = true flag in build.gradle when appropriate
• Have not changed source names
• Have explicitly kept the id if a source's name or language were changed
• Have tested the modifications by compiling and running the extension through Android Studio
• Have removed web_hi_res_512.png when adding a new extension

[AwkwardPeak7]

this conversion doesn't seem to work for me, it gives 404 and redirects to their admin page(?)

[vetleledaal]

The issue was that it was trying to rewrite cover URLs as well. Added a fragment for all chapter images so it can be identified in the interceptor.

The logic will be disabled if any 404 is seen during the URL rewrite, as this means a previous assumption is broken. I tried to provide feedback via toast, but that broke the images completely. Instead, additional text was added to the extension settings.