XLSX converter doesn't trim whitespace from column names

[albertchae]

example calculation_name on the calculates tab will result in an error

[linl33]

https://github.com/odk-x/app-designer/blob/9e06f420276a2c08f7e8ca5091b65aa3bc38ee0c/xlsxconverter/XLSXConverter2.js#L581-L587

        _.each(row, function(value, key){
            if(_.isString(value)){
                value = value.replace(/\r/g, "");
                value = value.trim();
            }
            outRow[key] = value;
        });

Calling trim on key should fix this issue.

[EstherPhebe]

@linl33 I'd like to work on this. From what I see the trim method should be called on the key parameter to remove the trailing whitespace. Will the key argument always be a string?

[linl33]

@EstherPhebe I've assigned this issue to you. Be sure to test thoroughly that fixing this issue doesn't break existing forms. Thanks!

key should always be a string given that it was used to index outRow.