* First draft of prop object type
* Add prop editor dialog in FRED
* prop sexps
* lua table prop support
* lab support
* lua mission access to props
* prop collision support
* use std::optional so the object->instance id is always valid
* allow props to block suns
* minor cleanup and remove arbitrary limit. Still limited to 500 objects.
* Sort props by category
* cleanup
* implement collision hooks
* parse prop flags and further ensure props are inited and closed correctly
* Add Cyborg's multi suggestions
* fix missing header
* add props to empty slots if available
* add multi signature
* fix rebase issues and match collisions to the new multithread style
* appease Clang the Conquerer
* save/parse mission prop classes by name
* Clean up comments and finish TODOs
* fix string errors
* clang wants this to be static now
* address feedback
* address feedback
* Use model num from prop info instead
* merge prop and ship collision group sexps together
* fix rebase bug
* address feedback
* fix name shadowing
* ship heavy submodel
* clang
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Co-authored-by: Asteroth <[email protected]>
