This fix is needed to address internal changes in the Garmin API, where service
endpoints that previously worked started returning 402 responses. Appears like
dropping the `modern` prefix from the endpoint paths fixes the issue.
Also, the authentication sequence has been updated to include a CSRF (Cross-Site
Request Forgery) token to closer mimic the behavior of the login sequence on the
official web page.
Co-authored-by: kfollesdal <kristoffer.follesdal@bkk.no>