Read text files as utf-8, instead of default os locale

On Windows, the default locale isn't utf8. Khoj had regressed to
reading files in OS specified locale encoding, e.g cp1252, cp949 etc.

It now explicitly uses utf8 encoding to read text files for indexing

Resolves #495, resolves #472

tests/test_text_search.py

@@ -1,26 +1,25 @@
 # System Packages
 import logging
+import locale
 from pathlib import Path
 import os
 
 # External Packages
 import pytest
-from khoj.utils.config import SearchModels
 
 # Internal Packages
 from khoj.utils.state import content_index, search_models
 from khoj.search_type import text_search
-from khoj.utils.rawconfig import ContentConfig, SearchConfig, TextContentConfig
 from khoj.processor.org_mode.org_to_jsonl import OrgToJsonl
 from khoj.processor.github.github_to_jsonl import GithubToJsonl
+from khoj.utils.config import SearchModels
 from khoj.utils.fs_syncer import get_org_files
+from khoj.utils.rawconfig import ContentConfig, SearchConfig, TextContentConfig
 
 
 # Test
 # ----------------------------------------------------------------------------------------------------
-def test_text_search_setup_with_missing_file_raises_error(
-    org_config_with_only_new_file: TextContentConfig, search_config: SearchConfig
-):
+def test_text_search_setup_with_missing_file_raises_error(org_config_with_only_new_file: TextContentConfig):
     # Arrange
     # Ensure file mentioned in org.input-files is missing
     single_new_file = Path(org_config_with_only_new_file.input_files[0])
@@ -29,7 +28,7 @@ def test_text_search_setup_with_missing_file_raises_error(
     # Act
     # Generate notes embeddings during asymmetric setup
     with pytest.raises(FileNotFoundError):
-        data = get_org_files(org_config_with_only_new_file)
+        get_org_files(org_config_with_only_new_file)
 
 
 # ----------------------------------------------------------------------------------------------------
@@ -48,6 +47,7 @@ def test_text_search_setup_with_empty_file_raises_error(
 def test_text_search_setup(content_config: ContentConfig, search_models: SearchModels):
     # Arrange
     data = get_org_files(content_config.org)
+
     # Act
     # Regenerate notes embeddings during asymmetric setup
     notes_model = text_search.setup(