Add "Syncronize all" to root tray menu

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## Feature request

**Which Nextcloud Version are you currently using:** 34.0.1

**Is your feature request related to a problem? Please describe.**
Previously it was possible to initiate a syncronization of all folders in the system tray. Now, since 34.0.0, this option is behind another two clicks. In OneDrive, for example, it is even more harder as you have to force stop and re-enable syncronization.

**Describe the solution you'd like**
Add "Syncronize all" to the root tray menu.