[release/8.0.1xx-rc2.2] Ensure that viewport calculations for iOS ScrollView account for content insets#18321

PureWeen merged 2 commits into

release/8.0.1xx-rc2.2dotnet/maui:release/8.0.1xx-rc2.2from

backport/pr-18277-to-release/8.0.1xx-rc2.2dotnet/maui:backport/pr-18277-to-release/8.0.1xx-rc2.2Copy head branch name to clipboard