refactor form code for required field validation errors

[cch5ng]

currently there are redundant strings defined for required field validation error messages in form.py and bugform.js. it would be good to investigate:

• which strings are actually used and which strings could be removed (leaning towards using the js-defined strings to keep but need to test)
• also verify that the error sections coming from form.py (in form.html) are still being used

relevant code sections: https://github.com/webcompat/webcompat.com/blob/master/webcompat/form.py#L44 (strings of form *_message)

https://github.com/webcompat/webcompat.com/blob/master/webcompat/static/js/lib/bugform.js#L18 (all helpText strings for this.inputs)

https://github.com/webcompat/webcompat.com/blob/master/webcompat/templates/home-page/form.html#L21 sections like {form.*.errors} which appear to be coming from form.py

[zoepage]

@cch5ng what is the status of that issue? :)

[cch5ng]

@zoepage I have not been working on this one; right now I'm mainly working on the Image Editor. thx...