Sync Edge Split Tabs

### Describe the feature you'd like to request

In Microsoft Edge (I'm on Version 121.0.2220.3 (Official build) dev (64-bit)), if I try to sync a split tab (there's a feature in Edge to split tabs and have 2 pages in one tab), Floccus will only sync the left tab.

### Describe the solution you'd like

Both tabs should be recognized and be synced. They don't have to be in split mode when it's downloaded (but if it can be it would be nice, and remembering that some tabs are pinned would be nice too).

### Describe alternatives you've considered

No alternative. I can't use split tabs together with Floccus sync tabs 🥲