Fix : When using multilingual option for event fields, all required language fields should be validated [SDESK-6869]

[devketanpro]

No description provided.

[MarkLark86]

Play around with those errors, as they still aren't showing up in the form (tried this locally).
The following should be visible upon errors:

See how the field in the form is highlighted red, with a message underneath stating that this field is required.
It would be good to have the same for multilingual fields too.

I believe this is done using the errors variable, and the key should be <field>.<language> for multilingual errors.
i.e.
errors['name.en'] = gettext('This field is required')
See the following attributes passed (shown via React dev tools)