fix(firebase_ui_auth): sendPasswordResetEmail should not be executed when isLoading=true

[kzrnm]

Description

Even when ForgotPasswordView has isLoading=true, sendPasswordResetEmail is executed the number of times the button is pressed.
I don't see any advantage for users to receive more than one email.

In this PR, if isLoading is true, the mail is not sent.

Related Issues

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