Add commit status summary table to reduce query from commit status table (#30223)

This PR adds a new table named commit status summary to reduce queries
from the commit status table. After this change, commit status summary
table will be used for the final result, commit status table will be for
details.

---------

Co-authored-by: Jason Song <i@wolfogre.com>

models/migrations/v1_23/v295.go

@@ -0,0 +1,18 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_23 //nolint
+
+import "xorm.io/xorm"
+
+func AddCommitStatusSummary(x *xorm.Engine) error {
+	type CommitStatusSummary struct {
+		ID     int64  `xorm:"pk autoincr"`
+		RepoID int64  `xorm:"INDEX UNIQUE(repo_id_sha)"`
+		SHA    string `xorm:"VARCHAR(64) NOT NULL INDEX UNIQUE(repo_id_sha)"`
+		State  string `xorm:"VARCHAR(7) NOT NULL"`
+	}
+	// there is no migrations because if there is no data on this table, it will fall back to get data
+	// from commit status
+	return x.Sync2(new(CommitStatusSummary))
+}