Emacs: notmuch-indicator version 1.0.0

This is a simple package that renders an indicator with email counters of the notmuch index on the Emacs mode line. The underlying mechanism is that of notmuch-count(1), which is used to find the number of items that match the given search terms. The user can define the queries and associate them with a character, optionally assigning a face to it.

Package name (GNU ELPA): notmuch-indicator
Git repo on SourceHut: https://git.sr.ht/~protesilaos/notmuch-indicator
- Mirrors:
  - GitHub: https://github.com/protesilaos/notmuch-indicator
  - GitLab: https://gitlab.com/protesilaos/notmuch-indicator
Mailing list: https://lists.sr.ht/~protesilaos/notmuch-indicator
Backronym: notmuch-… Increasingly in Need of Displaying Inconsequential Counters Alongside Trivia that Obscure Reality.

Below are the release notes.

Each counter in the entire indicator is now rendered with its own mouse hover. This effect makes it clear that the counters are interactive. Clicking on a counter terms the underlying search terms that produced it and produce a notmuch (notmuch.el) search buffer with them.
The fix I did that prevented the display of duplicate counters is now formalised in a tagged release. I observed a bug while starting from 0 emails, with notmuch-indicator-hide-empty-counters set to non-nil. The indicator would show multiple counters for the same search terms. Whereas we always want to start from a clean state.
The notmuch-indicator-refresh is a public function that supersedes the now-deprecated private function notmuch-indicator--refresh. The difference is one of forward guidance in how we maintain the package: this way we tell users that the given symbol is stable and will not change without notice.
Other miscellaneous tweaks are in place.