[TEST] Harden GeoShapeIntegrationTests.
`geo_point` doesn't allow null values

After upgrading to 1.1.0, sending null values to geo points produces the following error:

```
MapperParsingException[failed to parse]; nested: ElasticsearchParseException[geo_point expected];
```

Closes #5680.
Closes #5681.
[Test] added trace logging to refresh action to note which cluster version was used

Increase logging level for SearchWithRandomExceptionsTests.testRandomExceptions & MinDocCountTests to use the above and log cluster states on changes.