Added strict type checking to the project. (#236)

* Implement strict typing (WIP).

* changes

* Finish type checks

* Fix notification icon, matugen settings and update tsconfig.

* OSD Styling updates and added the ability to configure OSD duration.

customModules/cpu/computeCPU.ts

@@ -1,8 +1,6 @@
 // @ts-expect-error
 import GTop from 'gi://GTop';
 
-const defaultCpuData: number = 0;
-
 let previousCpuData = new GTop.glibtop_cpu();
 GTop.glibtop_get_cpu(previousCpuData);