refactor: move pushover into sub package, pull config into config package

Signed-off-by: Alix von Schirp <github@avonschirp.bootmedia.de>

config/jest.config.js

@@ -0,0 +1,7 @@
+/** @type {import('ts-jest').JestConfigWithTsJest} **/
+export default {
+  testEnvironment: "node",
+  transform: {
+    "^.+\.tsx?$": ["ts-jest", {}],
+  },
+};