Big Findy Tunes.

New Features:

• Show larger tab thumbnails when there is extra space. ‼️ 💯
• Add a search box to quickly filter your tabs. 🔍

Fixes:

• Click on find icon to focus the find bar. 🌁
• Toolbar icons correctly change color in dark themes. (Fixes #305.)
• Load thumbnails for all sites. 💅🖼 (Fixes #411, #415, #167, #353.)
• Make sure the splitter doesn’t grow too large. 🐞 (Fixes #414.)
• Resize on deleting a tab.
• Only show light pin if dark theme in linux.
• Don't show the really wide splitter in fullscreen. 👀 (Fixes #392.)