[DO NOT MERGE] 677 add version number to xform and endpoint to replace a form

closes #677 and #542 
This is actually in xlsforms where you can specify a `version` column in the `settings` sheet. That is why it is a user defined issue for the advanced users and for those not advanced we define it for them. To some extent we may need to check if it has changed during the xlsform update in the event a user is changing this on their end. This is not an internal spec so to speak, but an xlsform thing, for us it would does help to support this for users who are not aware of the feature as well as eventually handle this in exports.