Add 2fa for authentification (#383)

Fix user tests

Add swagger docs

Fix lint

Add totp check when logging in

Make totp enrollment work

Add migration for totp table

go mod vendor

Add routes for totp routes

Add route handler for totp routes

Add basic implementation to enroll a user in totp

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/383

pkg/user/user.go

@@ -37,6 +37,8 @@ type Login struct {
 	Username string `json:"username"`
 	// The password for the user.
 	Password string `json:"password"`
+	// The totp passcode of a user. Only needs to be provided when enabled.
+	TOTPPasscode string `json:"totp_passcode"`
 }
 
 // User holds information about an user