feat(fossil_metrics): add fossil_metrics module (#4874)

* feat(fossil_metrics): add fossil_metrics module

* Return early if not in a Fossil check-out

* Add more tests for fossil_metrics

* Move is in Fossil checkout check after module enabled check

* Update type for new toml version

* Update the config file schema

* Rework parsing of fossil diff output

* Fix Fossil check-out detection in subdirectories

* Use regex to only match expected fossil diff output

* Use shared ancestor scanning and fix detection on Windows

* Add note on minimum Fossil version

src/configs/starship_root.rs

@@ -39,6 +39,7 @@ pub const PROMPT_ORDER: &[&str] = &[
     "directory",
     "vcsh",
     "fossil_branch",
+    "fossil_metrics",
     "git_branch",
     "git_commit",
     "git_state",