Add reauthentication for husqvarna_automower (#109930)

* Add reauthentication for husqvarna_automower

* Remove unneded lines

* Don't extract token on reauth

* Update homeassistant/components/husqvarna_automower/config_flow.py

Co-authored-by: Joost Lekkerkerker <joostlek@outlook.com>

* Update tests/components/husqvarna_automower/conftest.py

Co-authored-by: Joost Lekkerkerker <joostlek@outlook.com>

* Use helper

* Test if authentication is done with the right account

* switch to ConfigFlowResult

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Co-authored-by: Joost Lekkerkerker <joostlek@outlook.com>