[API] Add more filters to issues search (#13514)

* Add time filter for issue search

* Add limit option for paggination

* Add Filter for: Created by User, Assigned to User, Mentioning User

* update swagger

* Add Tests for limit, before & since

models/issue.go

@@ -1100,6 +1100,8 @@ type IssuesOptions struct {
 	ExcludedLabelNames []string
 	SortType           string
 	IssueIDs           []int64
+	UpdatedAfterUnix   int64
+	UpdatedBeforeUnix  int64
 	// prioritize issues from this repo
 	PriorityRepoID int64
 }
@@ -1178,6 +1180,13 @@ func (opts *IssuesOptions) setupSession(sess *xorm.Session) {
 		sess.In("issue.milestone_id", opts.MilestoneIDs)
 	}
 
+	if opts.UpdatedAfterUnix != 0 {
+		sess.And(builder.Gte{"issue.updated_unix": opts.UpdatedAfterUnix})
+	}
+	if opts.UpdatedBeforeUnix != 0 {
+		sess.And(builder.Lte{"issue.updated_unix": opts.UpdatedBeforeUnix})
+	}
+
 	if opts.ProjectID > 0 {
 		sess.Join("INNER", "project_issue", "issue.id = project_issue.issue_id").
 			And("project_issue.project_id=?", opts.ProjectID)