Spotify Playback Speed por raphael m

Quickly change playback speed on Spotify Web because some songs just sound better faster or slower.

-- Release notes --

March 2025:
* Fixed playback rate not being set right away when changing value

February 2025:
* Fixed a bug where menu is hidden by 'Now Playing View' and 'Queue' sidebar

2023:
* Fixed preserve pitch setting not being remembered
* Fixed playback rate not being set right away when changing value
* Added more checks to ensure a bug causing playback speed of 0 doesn't get set.
* Fixed a bug from a recent Spotify Web update that caused the extension to not show up.
* Fixed a bug that was causing potential audio artifacts due to unintended playback speed changes coming from a recent Spotify Web update.
- Big thanks to Kamil K. for the help!