Settings and easy import of subscriptions

What's Changed

• Switch to meson by @Schmiddiii in #82
• Add initial settings by @Schmiddiii in #83
• Import subscriptions by @Schmiddiii in #84
• 🌐️ Update Russian translation by @daudix-UFO in #85
• 💄️ Optimize symbolic icon by @daudix-UFO in #86
• Update it.po by @albanobattistella in #87
• Update de.schmidhuberj.tubefeeder.desktop by @airon90 in #89
• Updated Dutch translation by @Vistaus in #91
• Update Czech translations by @vikdevelop in #92
• Update it.po by @airon90 in #90

Full Changelog: v1.8.5...v1.9.0