Gremlin is unable to search non-string properties when searched as a String after using in/out operation on a vertex

- Version: 0.5.3
- Storage Backend: cql, in-memory
- Expected Behavior: Gremlin should automatically convert the String argument to the corresponding datatype for the property as it is doing for simple queries when not traversing in and out of a vertex
- Current Behavior: Gremlin does not convert String argument to its equivalent non-String datatype

- Steps to Reproduce:

1. start gremlin.bat in windows

2. Execute below commands to load GraphOfTheGods

gremlin> graph = JanusGraphFactory.open('conf/janusgraph-inmemory.properties')
gremlin> GraphOfTheGodsFactory.loadWithoutMixedIndex(graph, true)
gremlin> g = graph.traversal()

3. Test the query.
gremlin> g.V().has('age',**'4500'**).valueMap()
==>[name:[neptune],age:[4500]]

4. Test the below query.
gremlin> g.V().has('name','neptune').out().in().has('age',**'4500'**).valueMap()
**Result is Empty**

5. Test the same query, now instead using String for age use the actual datatype
gremlin> g.V().has('name','neptune').out().in().has('age',**4500**).valueMap()
==>[name:[neptune],age:[4500]]
==>[name:[neptune],age:[4500]]
==>[name:[neptune],age:[4500]]

The issue exists in all the versions of gremlin.
The issue can also be reproduced with other datatypes such UUID, date etc.

I also changed the example-common program(PSA) to check if the issue is in gremlin console or the gremlin API.
In the example program I tested with adding UUID and date fields in schema, the issue got reproduced for those datatypes as well in the java program.

[example-common.zip](https://github.com/JanusGraph/janusgraph/files/6038703/example-common.zip)

### Stack Trace (if you have one)

```
paste stack trace here
```

Start by reproducing the two Gremlin traversals in the issue with the in-memory backend and compare the direct property lookup with the lookup after out().in(). Check the traversal and property-query paths involved in datatype conversion, including the UUID and date cases described. Done means string values such as '4500' match equivalent non-string properties consistently after traversal, with regression coverage for the reported cases.

Written by the indexing model from the issue text.