CB-380: "Write a review" error messages don't give any context

[amCap1712]

There are two things about the issue in question:-

1. Not a valid choice issue. This occurs because of the default value of the Flask Validator. However, the specific message that should be displayed for the validation failure has an extra Not a Valid Choice message. I checked the WTF forms docs and they recommend that InputRequired be used unless there is a specific reason to use DataRequired. Using, InputRequired also fixes the issue.
   However, there are other places in the codebase where DataRequired is used. Do we want to change those to InputRequired as well ?

2. Changing the exclamation to period is simple. But a livegrep shows ! are used at quite a few places. Do we want to change them as well, if yes which ones ?

JIRA: CB-380

[alastair]

Let's open a ticket for replacing DataRequired -> InputRequired.

Let's not worry about changing all of the !'s for now. Many of the search results that you linked are in tests, so we don't need to change those. If we're editing some part of the code and see a ! that doesn't make sense we can slowly change them at that time. While we're at it can we remove the ! from "You need to choose a license!"? My preference is for these error messages to not have a . at the end of them