Add new setting to toggle seek on progress bar on lock screen

[GianniCarlo]

Purpose

• Add new setting inside the settings-player-controls screen to enable / disable scrubbing on the progress bar on the lock screen (or in the control center)

Things to be aware of / Things to focus on

• There's now a 'More' button inside the mini controls screen that opens from the player screen, to open the settings player controls
• Also some VoiceOver updates for the mini controls screen, so the + and - icons are accessible