Updated by "Cleanup translation files" hook in Weblate.

Co-authored-by: Weblate <noreply@weblate.org>
Translate-URL: https://weblate.nheko.im/projects/nheko/nheko-master/
Translation: Nheko/nheko

Also fixes some issues where nested transactions will poison the
verification cache.

We explicitly set a parent. We can't assign to
ApplicationWindow.transientParent though, only to
Window.transientParent, so we just call setTransientParent in C++.

Currently translated at 100.0% (493 of 493 strings)

Co-authored-by: -- <spdrespudro@yahoo.com>
Translate-URL: https://weblate.nheko.im/projects/nheko/nheko-master/fi/
Translation: Nheko/nheko

There are probably a few things wrong with this, but I'm going to call it good enough for an initial commit

Also fix a lot of warnings.