Drop old code to sync files on server filesystem. Clean cli, init paths

This stale code was originally used to index files on server file
system directly by server. We currently push files to sync via API.

Server side syncing of remote content like Github and Notion is still
supported. But old, unused code for server side sync of files on
server fs is being cleaned out.

New --log-file cli args allows specifying where khoj server should
store logs on fs. This replaces the --config-file cli arg that was
only being used as a proxy for deciding where to store the log file.

- TODO
  - Tests are broken. They were relying on the server side content
    syncing for test setup

tests/conftest.py

@@ -33,7 +33,7 @@ from khoj.utils import fs_syncer, state
 from khoj.utils.config import SearchModels
 from khoj.utils.constants import web_directory
 from khoj.utils.helpers import resolve_absolute_path
-from khoj.utils.rawconfig import ContentConfig, ImageSearchConfig, SearchConfig
+from khoj.utils.rawconfig import ContentConfig, SearchConfig
 from tests.helpers import (
     AiModelApiFactory,
     ChatModelFactory,
@@ -69,12 +69,6 @@ def search_config() -> SearchConfig:
     model_dir.mkdir(parents=True, exist_ok=True)
     search_config = SearchConfig()
 
-    search_config.image = ImageSearchConfig(
-        encoder="sentence-transformers/clip-ViT-B-32",
-        model_directory=model_dir / "image/",
-        encoder_type=None,
-    )
-
     return search_config
 
 
@@ -301,7 +295,6 @@ def chat_client_with_large_kb(search_config: SearchConfig, default_user2: KhojUs
 @pytest.mark.django_db
 def chat_client_builder(search_config, user, index_content=True, require_auth=False):
     # Initialize app state
-    state.config.search_type = search_config
     state.SearchType = configure_search_types()
 
     if index_content:
@@ -349,7 +342,6 @@ def large_kb_chat_client_builder(search_config, user):
     import tempfile
 
     # Initialize app state
-    state.config.search_type = search_config
     state.SearchType = configure_search_types()
 
     # Create temporary directory for large number of test files
@@ -470,12 +462,8 @@ def fastapi_app():
 
 @pytest.fixture(scope="function")
 def client(
-    content_config: ContentConfig,
-    search_config: SearchConfig,
     api_user: KhojApiUser,
 ):
-    state.config.content_type = content_config
-    state.config.search_type = search_config
     state.SearchType = configure_search_types()
     state.embeddings_model = dict()
     state.embeddings_model["default"] = EmbeddingsModel()