POST /v2/entities behaves as options=keyValues when this parameter is not set

[fgalan]

Raised at #1687 (comment). Probably this is something that we missed before closing #1259.

In particular, the following changes should be done:

• Right attribute value check for isObject in this case, e.g. if (! object) error()
• Change the attribute "filling" logic to remove the heuristic in old versions (i.e. the one that look for "value" and if it doesn't find it, assumes that the value of the JSON property is the value of the attribute). The "filling" logic should be as dummy as the current way of working is, to avoid "hiding" bugs like in this case.

Not sure if this could affect other operations apart from POST /v2/entities. I rely on the exhaustive acceptance test done by @iariasleon in order to raise new cases ;)

[fgalan]

Maybe a bit side-topic, but as part of this issue, the /test/functionalTest/cases/0999_update_single_attr_value_by_eid/update_single_attr_value_by_eid_error_handling.test.DISABLED should be fixed.

[fgalan]

Fixed in PR #1701, but update_single_attr_value_by_eid_error_handling.test.DISABLED fixing pending.

[fgalan]

The sub-task related with the DISABLED test has been completed in PR #1709. Closing issue.