Following the correction of the Trust Loader, properly test and document all business flows and simplify the code when possible

Example:

• (added): Correct the npm goal patch-dsu-explorer to change the DSU Explorer's loader
• Have no hardcoded strings (there are still some left);
• Simplify logic when applicable (low priority);
• Properly test the business logic (at least the DSU related process flows, leave the UI stuff for later e2e tests)
• properly document the sequence flows for the loader (use mermaid for it. This will force you to have the knowledge of how it works and also forces you to document process flows).
• Implement missing features, present in Romsofts loader (change pin, change password, etc)