[API] generalize list header (#16551)

* Add info about list endpoints to CONTRIBUTING.md

* Let all list endpoints return X-Total-Count header 

* Add TODOs for GetCombinedCommitStatusByRef

* Fix models/issue_stopwatch.go

* Rrefactor models.ListDeployKeys

* Introduce helper func and use them for SetLinkHeader related func

1 files changed, 10 insertions, 0 deletions

diff --git a/models/issue_label.go b/models/issue_label.go
index d1ff469236..5d50203b5a 100644
--- a/models/issue_label.go
+++ b/models/issue_label.go
@@ -444,6 +444,11 @@ func GetLabelsByRepoID(repoID int64, sortType string, listOptions ListOptions) (
 	return getLabelsByRepoID(x, repoID, sortType, listOptions)
 }
 
+// CountLabelsByRepoID count number of all labels that belong to given repository by ID.
+func CountLabelsByRepoID(repoID int64) (int64, error) {
+	return x.Where("repo_id = ?", repoID).Count(&Label{})
+}
+
 // ________
 // \_____  \_______  ____
 //  /   |   \_  __ \/ ___\
@@ -556,6 +561,11 @@ func GetLabelsByOrgID(orgID int64, sortType string, listOptions ListOptions) ([]
 	return getLabelsByOrgID(x, orgID, sortType, listOptions)
 }
 
+// CountLabelsByOrgID count all labels that belong to given organization by ID.
+func CountLabelsByOrgID(orgID int64) (int64, error) {
+	return x.Where("org_id = ?", orgID).Count(&Label{})
+}
+
 // .___
 // |   | ______ ________ __   ____
 // |   |/  ___//  ___/  |  \_/ __ \