A number of website now prompts for username and password on separate pages, so made sure the password is auto-filled as soon as found, before trying to find the username field.

Also improve the username matching algorithm.

It will now consider other candidates if one is not 'visible'

Some site have their Register form, Reset Password form etc... as hidden panels.
So only select the first visible password field when autofilling from Vault

If no visible password field can be found, select the first one

Also try to clean up any old env

Read any other username/password pairs from any given secret on top of the default "username"/"password" pair

For example, if a secret has the following keys:
{
  "username": "myusername",
  "password": "mypassword",
  "username.2": "other username",
  "password.2": "other password",
  "username for test": "test username",
  "password for test": "test password"
}

then 3 sets of credentials will be loaded for that one secret:
myusername/mypassword
other username/other password
and
test username/test password

To avoid to many false positive, only widen the search for a potential username field to generic text fields when a password field is in a form or the user manually requested credentials to be filled on the current web page