Add password length filter in `register_new_user` function.

[1naveengiri]

I found there is no way to change password length param of wp_generate_password function.
I found there is no filter to extend the password length.

there should be one filter so that if anyone want to extend password length during user registration they could.

ref: wp-includes/user.php
line number : 2343
Function name: register_new_user()

[1naveengiri]

Fixed in this patch.

[SergeyBiryukov]

Related: #37674

[1naveengiri]

@SergeyBiryukov Thanks for checking it.