refactor: update nostr-tools imports for better tree shaking

Changes:
- Import specific functions from nostr-tools instead of full module
- Replace nip06.accountFromExtendedKey with direct import
- Update related function calls to use imported version

This change reduces bundle size by enabling better tree shaking
of unused nostr-tools functionality.

src/views/AccountViewView.vue

@@ -895,7 +895,7 @@ import { AxiosError } from "axios";
 import { Buffer } from "buffer/";
 import Dexie from "dexie";
 import "dexie-export-import";
-import { importDB, ImportProgress } from "dexie-export-import";
+import { ImportProgress } from "dexie-export-import";
 import { LeafletMouseEvent } from "leaflet";
 import * as R from "ramda";
 import { IIdentifier } from "@veramo/core";