StyleRuleCounterStyle currently stores `StyleProperties` besides `CSSCounterStyleDescriptors`. This is used for facilitating serialization and read/write for the CSSOM api. We can get rid of the `StyleProperties` member and use only `CSSCounterStyleDescriptors` after we write a serializer for each descriptor and adapt the setter function for setting only the `CSSCounterStyleDescriptors`
<rdar://problem/107267784>
Pull request: https://github.com/WebKit/WebKit/pull/12168
Committed 262396@main (b96c4a014f18): <https://commits.webkit.org/262396@main> Reviewed commits have been landed. Closing PR #12168 and removing active labels.