[Databuckets] Nested Databuckets Protections and Improvements (#4748)

* Check for valid JSON before using it

* Do not allow nested keys to set be set an expiration

* Prevent overwriting of existing object or array

* Nested deletion support

* Update data_bucket.cpp

* Test cases

* More test cases, fix

* Update databuckets.cpp

* Update databuckets.cpp

* Basic databucket tests

* Update databuckets.cpp

* Update databuckets.cpp

utils/scripts/build/linux-build.sh

@@ -56,8 +56,9 @@ echo "# Running shared_memory"
 echo "# Running NPC hand-in tests"
 ./bin/zone tests:npc-handins 2>&1 | tee test_output.log
 ./bin/zone tests:npc-handins-multiquest 2>&1 | tee -a test_output.log
+./bin/zone tests:databuckets 2>&1 | tee -a test_output.log
 
-if grep -E -q "QueryErr|Error" test_output.log; then
+if grep -E -q "QueryErr|Error|FAILED" test_output.log; then
     echo "Error found in test output! Failing build."
     exit 1
 fi