Do not expose table related exception if feature is not enabled.

[Yuqi-Du]

So if the column validation failed before the feature flag check, it won’t return error like TABLE_FEATURE_NOT_ENABLED, instead it will return table related stuff. We should do feature checks before these validations happen.

For example, with Feature-Flag-tables set as False

{
    "createTable": {
        "name": "allcolumns",
        "definition": {
            "columns": {
                "id": {
                    "type": "text"
                },
                "age": {
                    "type": "int"
                },
                "image_data": {
                    "type": "blob"
                }

            },
            "primaryKey": "id"
        }
    }
}


{
    "errors": [
        {
            "message": "Unsupported column types: Invalid column type: blob",
            "errorCode": "TABLE_COLUMN_TYPE_UNSUPPORTED"
        }
    ]
}

[tatu-at-datastax]

I can reproduce this, but the problem unfortunately seems to difficult to resolve. The problem is that this "validation" is part of JSON deserialization of CreateTableCommand by Quarkus (using Jackson) which converts from column type String into ColumnDataType via ColumnType. And lookup for ColumnType throws the exception.

ApiFeature checking can only be done when in KeyspaceResource.postCommand(), but to get there, KeyspaceCommand must have been deserialized; doing which throws exception.

Not sure if or how this could be resolved: will create a PR simply reproducing the issue first.

[tatu-at-datastax]

I have a PR for fix (#1470) but not 100% sure if we want to pursue that approach; to be discussed.