New bullets #779

Is there any interest in adding new unicode bullets? Right now the ones I would like would be for questions and TODOs. Something like this:

cli::cli_bullets(c("?" = "This is a question", "[]" = "This is a TODO"))

With the symbols (in red):

cli::symbol$fancy_question_mark
#> [1] "❓"
cli::symbol$checkbox_off
#> [1] "☐"

^{Created on 2025-07-21 with reprex v2.1.1}

I'm happy to make a PR if the answer is yes.