FacetResult class isn't exposed anymore

OAK-3847 exposed FacetResult (rather org.apache.jackrabbit.oak.query.facet package) to easily consume extracted facet data. That exported package got removed during OAK-6304 (as noted in this comment [1]).

We need to export that class - maybe that class makes sense as part of oak-query-spi module - that still needs to be checked as assessed btw (ie if we can simply re-enable the removed export AND that its current place in oak-core still makes sense or not).

anchela, would you remember what was the warning that was observed without removing this export (disclaimer: I still feel that it belongs in oak-query-spi... I'm just trying to have all data available).

[1]: https://issues.apache.org/jira/browse/OAK-6304?focusedCommentId=16042721&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-16042721