Close/reopen issues by keywords in titles and comments (#8866)

* Add close/reopen from comment functionality

* Fix comment

* Rewrite closing/reopening template

* Check xref permissions, move action to services/pull

* Fix RefIsPull field

* Add xref tests

* Fix xref unique filter

* Only highlight keywords for actionable xrefs

* Fix xref neuter filter

* Fix check return status

* Restart CI

modules/references/references.go

@@ -350,3 +350,8 @@ func findActionKeywords(content []byte, start int) (XRefAction, *RefSpan) {
 	}
 	return XRefActionNone, nil
 }
+
+// IsXrefActionable returns true if the xref action is actionable (i.e. produces a result when resolved)
+func IsXrefActionable(a XRefAction) bool {
+	return a == XRefActionCloses || a == XRefActionReopens
+}