Add email reminders (#743)

Fix tests

Expose email reminder setting through jwt

Set reminders on by default

Fix lint

Make user email configurable

Expose email reminder setting through /info

Don't try to send any reminders if none were found

More spacing for buttons

Fix db time format

Enable reminders by default

Make emails look more like the frontend

Add config to disable it

Add sending emaisl

Add getting all task users and reminding them

Add getting the next reminder in a cron

Move task reminder to separate file

Add cron

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/743
Co-Authored-By: konrad <konrad@kola-entertainments.de>
Co-Committed-By: konrad <konrad@kola-entertainments.de>

pkg/user/user.go

@@ -62,6 +62,9 @@ type User struct {
 	Issuer  string `xorm:"text null" json:"-"`
 	Subject string `xorm:"text null" json:"-"`
 
+	// If enabled, sends email reminders of tasks to the user.
+	EmailRemindersEnabled bool `xorm:"bool default true" json:"-"`
+
 	// A timestamp when this task was created. You cannot change this value.
 	Created time.Time `xorm:"created not null" json:"created"`
 	// A timestamp when this task was last updated. You cannot change this value.
@@ -322,6 +325,7 @@ func UpdateUser(user *User) (updatedUser *User, err error) {
 			"avatar_file_id",
 			"is_active",
 			"name",
+			"email_reminders_enabled",
 		).
 		Update(user)
 	if err != nil {