feat: add emacs-jupyter completion backend for acm in org babel

[sawyerzheng]

add a emacs-jupyter backend for acm babel completion

1. This backend can be activated by set acm-enable-jupyter to t
2. This backend only work when in a org-mode source code block and its language starts with "jupyter"
3. It still can make completion even though the import statement in a previous source code block
4. It need to start the jupyter in the org mode buffer first

[sawyerzheng]

new commit, (1) moved lsp-bridge-jupyter-complete function to acm-backend-jupyter.el (2) filtered the candidate with the current-symbol before cursor when current-symbol is a string

[manateelazycat]

Thanks