feat(magic): add run_personal and run_shared magic commands

[nunogoncalves03]

This PR introduces the run_personal and run_shared magic commands. These commands are wrappers for downloading and executing a personal or shared file. After its execution, the local file created is deleted.

# Load commands
%load_ext singlestoredb.magics

# Line usage
%run_personal personal_file.ipynb
%run_personal {{ sample_notebook_name }}

%run_shared shared_file.ipynb
%run_shared {{ sample_notebook_name }}

cc: @ricardoasmarques @kanitsharma

[nunogoncalves03]

How can we automatically load these commands on the notebook startup instead of executing %load_ext?

[kesmit13]

I know the sqlx magic used the top-level namespace, but I think we should avoid that here since these are very specific to SingleStore. I think we should add a magics subdirectory to singlestoredb and put all of our SingleStore-specific magics in that module and load them all at once (i.e., %load_ext singlestoredb.magics).