Bugfix/modify document coordinator (#3266)
Bugfix/modify document coordinator (#3266)

* Fixed ModifyDocument on coordinator. It uses the internally optimized function to extract _key values, which fails on Compact objects

* do not crash server when passing invalid document key type

hkernbach/arangodb,fceller/arangodb,Simran-B/arangodb,fceller/arangodb,arangodb/arangodb,arangodb/arangodb,hkernbach/arangodb,wiltonlazary/arangodb,arangodb/arangodb,graetzer/arangodb,hkernbach/arangodb,hkernbach/arangodb,fceller/arangodb,graetzer/arangodb,fceller/arangodb,arangodb/arangodb,wiltonlazary/arangodb,graetzer/arangodb,wiltonlazary/arangodb,fceller/arangodb,Simran-B/arangodb,graetzer/arangodb,fceller/arangodb,arangodb/arangodb,graetzer/arangodb,hkernbach/arangodb,Simran-B/arangodb,wiltonlazary/arangodb,graetzer/arangodb,Simran-B/arangodb,graetzer/arangodb,fceller/arangodb,wiltonlazary/arangodb,graetzer/arangodb,Simran-B/arangodb,Simran-B/arangodb,fceller/arangodb,graetzer/arangodb,hkernbach/arangodb,fceller/arangodb,hkernbach/arangodb,Simran-B/arangodb,wiltonlazary/arangodb,graetzer/arangodb,hkernbach/arangodb,Simran-B/arangodb,fceller/arangodb,Simran-B/arangodb,arangodb/arangodb,wiltonlazary/arangodb,hkernbach/arangodb,hkernbach/arangodb,hkernbach/arangodb,hkernbach/arangodb,hkernbach/arangodb,graetzer/arangodb,arangodb/arangodb,wiltonlazary/arangodb,graetzer/arangodb,graetzer/arangodb,graetzer/arangodb,arangodb/arangodb,hkernbach/arangodb,Simran-B/arangodb