refactor(settings): simplify $getSettings to $getMasterSettings

- Rename $getSettings to $getMasterSettings for clarity
- Remove unused account-specific logic (never called with accountDid)
- Simplify method signature by removing unused key parameter
- Update all 8 call sites and interface definitions
- Maintain backward compatibility for all existing functionality

All calls to $getSettings used MASTER_SETTINGS_KEY, so the complex
branching logic for account-specific settings was unnecessary.

src/views/ContactAmountsView.vue

@@ -124,7 +124,7 @@ import {
   NOTIFY_CONFIRMATION_RESTRICTION,
 } from "../constants/notifications";
 import { Contact } from "../db/tables/contacts";
-import { MASTER_SETTINGS_KEY } from "../db/tables/settings";
+
 import { GiveSummaryRecord, GiveActionClaim } from "../interfaces";
 import { AgreeActionClaim } from "../interfaces/claims";
 import {
@@ -223,7 +223,7 @@ export default class ContactAmountssView extends Vue {
       const contact = await this.$getContact(contactDid);
       this.contact = contact;
 
-      const settings = await this.$getSettings(MASTER_SETTINGS_KEY);
+      const settings = await this.$getMasterSettings();
       this.activeDid = settings?.activeDid || "";
       this.apiServer = settings?.apiServer || "";