Fix reading of http password and ha_key

[cebtenzzre]

AppDaemon 4.5.0 migrated the configuration to use Pydantic models. These models use SecretStr for fields that contain secrets.

This seems to have caused two regressions, because of the automatic obfuscation that converts str(SecretStr('abc')) -> '**********'.

1. Password login became impossible, because HTTP.password came via model_dump(), which obfuscates secrets.
2. x-ha-access was no longer set correctly, because it did not unwrap ha_key before using it.

This is fixed by calling get_secret_value() on the SecretStr in both cases.

I have confirmed that password login works again after this fix.

Fixes #2462

[acockburn]

Thanks!