Provide cross-reference information on objects

Provide cross-reference info option when I right-click on a group & host object. Cross-reference info provides a list of areas that references this object. If referenced, this tells me not to delete, rename, move this object unless I first check, and remediate if necessary, the referencing items (eg. datasource applies-to, alert rules, dashboard charts, reports, etc). Because there is currently no referential integrity check done by Lomo, I believe this feature can be helpful in preventing a user unknowingly break a function.