User forms (login/register/reset_password) should have specific errors bag containers instead of sharing the default one

[chatelardfrancois]

Context :
I have been asked to add login/register and reset_password form via popups so every form are rendered on the same html pages

Problem :
When a form encounters errors after submission, i have to repopen the correct popup (because page reloaded), this is why i check for errors but as every form share the same error bag ('default') i am not able to know wich form the error come from.

A specific container name for each form instead of using the default one could solve this problem

[chatelardfrancois]

Seems to be already the case for the user register form

Could be great to also have user.login and user.reset_password instead of "default" for those forms

[ryanmitchell]

This is already included as part of statamic/cms#8924