Sponsor Login Controller

[LightningBoltz21]

Fixes issue #5322. NOTE: the functionality of the controller has not been tested yet, but I'm making a PR so what I have so far can be reviewed.

[LightningBoltz21]

I believe the linting is failing because Pint and PHPCS have conflicting documentation.

For example: valid in Pint, not valid in PHPCS $result = $sponsorUser->attemptLoginUsingOneTimePassword((string) $request->input('otp'));

not valid in Pint, valid in PHPCS $result = $sponsorUser->attemptLoginUsingOneTimePassword( (string) $request->input('otp'));