* utils: expand `~` on execute_command()

* feat: add widget slider

* slider: queue setter to avoid racing

* slider: queue get to avoid possible racing with set

* slider: doc sync

* slider: avoid dead loop on queue_get(), just in case

* slider: expand cmd with predefined pattern

* Ported slider to GTK4

* Added CSS to match the other widgets

* Updated doc with information about "$value"

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Co-authored-by: Erik Reider <35975961+ErikReider@users.noreply.github.com>