feat(command completion): add lsp proxys for command completion

[MarcMcIntosh]

TBD

Should we add a bearer token check the the endpoint like we do with chat?

To run

add the following to the lsp.cfg file

{
    ...
    "interrupt_when_file_appears": "%FLAG_RESTART_LSP%",
    "command_line": [
        ...
        "--vecdb",
        "-f", "/home/user/.refact/tmp/unpacked-files/train_set.jsonl"
    ],
}