Improve Indexing Text Entries (#535)

Major
- Ensure search results logic consistent across migration to DB, multi-user
- Manually verified search results for sample queries look the same across migration
 - Flatten indexing code for better indexing progress tracking and code readability

Minor
- a4f407f Test memory leak on MPS device when generating vector embeddings
- ef24485 Improve Khoj with DB setup instructions in the Django app readme (for now)
- f212cc7 Arrange remaining text search tests in arrange, act, assert order
- 022017d Fix text search tests to test updated indexing log messages

src/database/adapters/__init__.py

@@ -1,4 +1,3 @@
-import secrets
 from typing import Type, TypeVar, List
 from datetime import date
 import secrets
@@ -36,9 +35,6 @@ from database.models import (
     OfflineChatProcessorConversationConfig,
 )
 from khoj.utils.helpers import generate_random_name
-from khoj.utils.rawconfig import (
-    ConversationProcessorConfig as UserConversationProcessorConfig,
-)
 from khoj.search_filter.word_filter import WordFilter
 from khoj.search_filter.file_filter import FileFilter
 from khoj.search_filter.date_filter import DateFilter