This was previously broken in a regression from https://github.com/silverstripe/silverstripe-userforms/pull/575
where the fields themselves could still be toggled, but the jQuery event dispatches for the form steps
were removed. This pull request re-introduces those jQuery event triggers when hiding and showing
editable form fields via display rules.
After testing it seems that having multiple user defined forms on a page
has already been added as a feature. However various load time dynamically
generated javascript segments had not been adapted to suit. Now they
have.
Also fixed a variable that no longer exists in the external requirements
from preventing a webpack build.
Mostly to do with translations, however the errors meant the front end
forms largely didn't work at all. Some of this was to do with the scoping
of `this` in es6 arrow functions, compared to the legacy code with entwine
that uses the fuller `function` definition. Reinstate missing dependency
for translations to function too.
