feat: add get all versions (backport #11124) (#11144)

* feat: add get all versions (#11124)

* add get all versions

* add changelog entry

(cherry picked from commit d624a65)

* fix conflicts and remove interface break

Co-authored-by: Marko <marbar3778@yahoo.com>

store/iavl/store.go

@@ -144,6 +144,11 @@ func (st *Store) VersionExists(version int64) bool {
 	return st.tree.VersionExists(version)
 }
 
+// GetAllVersions returns all versions in the iavl tree
+func (st *Store) GetAllVersions() []int {
+	return st.tree.(*iavl.MutableTree).AvailableVersions()
+}
+
 // Implements Store.
 func (st *Store) GetStoreType() types.StoreType {
 	return types.StoreTypeIAVL