Also allow webtoon side padding to be any amount between 0 - 25%.
(cherry picked from commit 2f0133986a60fbd4218e32fce19df6171bad4e71)
# Conflicts:
# app/src/main/java/eu/kanade/tachiyomi/ui/reader/setting/ReaderSettingsSheet.kt
# app/src/main/res/layout/reader_pager_settings.xml
# app/src/main/res/layout/reader_webtoon_settings.xml