Deep link to org-mode entries. Deep link by line number in uri

Use url fragment schema for deep link URIs, borrowing from URL/PDF
schemas. E.g file:///path/to/file.txt#line=<line_no>&#page=<page_no>

Compute line number during (recursive) org-mode entry chunking.

Thoroughly test line number in URI maps to line number of chunk in
actual org mode file.

This deeplink URI with line number is passed to llm as context to
better combine with line range based view file tool.

Grep tool already passed matching line number. This change passes
line number in URIs of org entries matched by the semantic search tool

tests/data/org/main_readme.org

@@ -3,7 +3,7 @@
 
   All data is processed locally. User can interface with khoj app via [[./interface/emacs/khoj.el][Emacs]], API or Commandline
 
-** Dependencies
+** Dependencies [[id:123-421-121-12]]  :TAG1:@TAG1_1:
    - Python3
    - [[https://docs.conda.io/en/latest/miniconda.html#latest-miniconda-installer-links][Miniconda]]
 
@@ -22,7 +22,7 @@
    #+end_src
 
 ** Use
-*** *Khoj via Emacs*
+*** *Khoj via Emacs*  [[https://khoj.dev][link to khoj website]]  :@EMACS:CLIENT_1:KHOJ:
      - [[https://github.com/khoj-ai/khoj/tree/master/interface/emacs#installation][Install]] [[./interface/emacs/khoj.el][khoj.el]]
      - Run ~M-x khoj <user-query>~ or Call ~C-c C-s~