The questionnaire validator was validating whether the sms.prompt was empty
As sms parts are being defined by the presence of smsSplitSeparator character in the sms.prompt, the prompt wasn't empty when there are parts
Solution
When validating the sms.prompt consider the presence of `smsSplitSeparator and analyze each part individually
For propagating the errors for each part I had to add an index into the error message so the component in charge of rendering them knows which part is having issues
Identifying the bug
sms.promptwas emptysmsSplitSeparatorcharacter in thesms.prompt, the prompt wasn't empty when there are partsSolution
sms.promptconsider the presence of `smsSplitSeparator and analyze each part individuallyEvidence
on staging - without the changes
https://github.com/instedd/surveda/assets/13237343/624bdb78-31a0-4a2c-8d8d-c055eb875d51
locally - after the changes
https://github.com/instedd/surveda/assets/13237343/a9aa75f6-049f-4047-8b57-49f65180bc19
closes #2328