exp: Unify dvc exp list and show output (#9808)

* use _describe in exp list

* fix pre-commit checks

* simplistic fix

* single _describe, too complex

* slightly simpler

* even simpler

* simple, but with regex

* less substitutions

* describe public

* name handling in UI (tests need updating)

* fixed old tests

* lazy imports

---------

Co-authored-by: Tibor Mach <[email protected]>

tests/func/experiments/test_save.py

@@ -67,11 +67,12 @@ def test_exp_save_after_commit(tmp_dir, dvc, scm):
     dvc.experiments.save(name="exp-1", force=True)
 
     tmp_dir.scm_gen({"new_file": "new_file"}, commit="new baseline")
+    baseline_new = scm.get_rev()
     dvc.experiments.save(name="exp-2", force=True)
 
     all_exps = dvc.experiments.ls(all_commits=True)
     assert all_exps[baseline][0][0] == "exp-1"
-    assert all_exps["refs/heads/master"][0][0] == "exp-2"
+    assert all_exps[baseline_new][0][0] == "exp-2"
 
 
 def test_exp_save_with_staged_changes(tmp_dir, dvc, scm):