Idle time picker shouldn't be limited to tasks from currently viewed project

[kryptot7]

Related to #3180

Problem Statement

When filing away untracked time, if I have the main window focused on a specific project, I will only be able to add that untracked time to a task from that specific project.
This is doubly frustrating due to #3180, which means the only solution is to create a temporary task, move it to the correct project, and then manually combine the time data.

❔ Possible Solution

Allow the untracked time to be added to any task in the database.

⤴️ Describe alternatives you've considered

• Make the current behavior optional
• If allowing a search of all tasks in the database is too broad, choose from tasks that are not in the backlog. Or, eliminate completed tasks from previous days. Or, only search the first 10000 (or some other arbitrary number) tasks found...or after the 10000th task in the list, only list completed tasks.

➕ Additional context

Thank you for developing Super Productivity!

[github-actions]

Thank you very much for opening up this issue! I am currently a bit overwhelmed by the many requests that arrive each week, so please forgive me, if I fail to respond personally. I am still very likely to at least skim read your request and I'll probably try to fix all (real) bugs if possible and I will likely review every single PR being made (please, give me a heads up if you intent to do so) and I will try to work on popular requests (please upvote via thumbs up on the original issue) whenever possible, but trying to respond to every single issue over the last years has been kind of draining and I need to adjust my approach for this project to remain fun for me and to make any progress with actually coding new stuff. Thanks for your understanding!