Implement recent commits graph (#29210)

This is the implementation of Recent Commits page. This feature was
mentioned on #18262.

It adds another tab to Activity page called Recent Commits. Recent
Commits tab shows number of commits since last year for the repository.

routers/web/repo/recent_commits.go

@@ -0,0 +1,41 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package repo
+
+import (
+	"errors"
+	"net/http"
+
+	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/context"
+	contributors_service "code.gitea.io/gitea/services/repository"
+)
+
+const (
+	tplRecentCommits base.TplName = "repo/activity"
+)
+
+// RecentCommits renders the page to show recent commit frequency on repository
+func RecentCommits(ctx *context.Context) {
+	ctx.Data["Title"] = ctx.Tr("repo.activity.navbar.recent_commits")
+
+	ctx.Data["PageIsActivity"] = true
+	ctx.Data["PageIsRecentCommits"] = true
+	ctx.PageData["repoLink"] = ctx.Repo.RepoLink
+
+	ctx.HTML(http.StatusOK, tplRecentCommits)
+}
+
+// RecentCommitsData returns JSON of recent commits data
+func RecentCommitsData(ctx *context.Context) {
+	if contributorStats, err := contributors_service.GetContributorStats(ctx, ctx.Cache, ctx.Repo.Repository, ctx.Repo.CommitID); err != nil {
+		if errors.Is(err, contributors_service.ErrAwaitGeneration) {
+			ctx.Status(http.StatusAccepted)
+			return
+		}
+		ctx.ServerError("RecentCommitsData", err)
+	} else {
+		ctx.JSON(http.StatusOK, contributorStats["total"].Weeks)
+	}
+}