Add user blocking (#29028)

Fixes #17453

This PR adds the abbility to block a user from a personal account or
organization to restrict how the blocked user can interact with the
blocker. The docs explain what's the consequence of blocking a user.

Screenshots:


![grafik](4ed884f3-e06a-4862-afd3-3b8aa2488dc6)


![grafik](ae6d4981-f252-4f50-a429-04f0f9f1cdf1)


![grafik](ca153599-5b0f-4b4a-90fe-18bdfd6f0b6b)

---------

Co-authored-by: Lauris BH <lauris@nix.lv>

routers/web/user/setting/block.go

@@ -0,0 +1,38 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package setting
+
+import (
+	"net/http"
+
+	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/setting"
+	shared_user "code.gitea.io/gitea/routers/web/shared/user"
+	"code.gitea.io/gitea/services/context"
+)
+
+const (
+	tplSettingsBlockedUsers base.TplName = "user/settings/blocked_users"
+)
+
+func BlockedUsers(ctx *context.Context) {
+	ctx.Data["Title"] = ctx.Tr("user.block.list")
+	ctx.Data["PageIsSettingsBlockedUsers"] = true
+
+	shared_user.BlockedUsers(ctx, ctx.Doer)
+	if ctx.Written() {
+		return
+	}
+
+	ctx.HTML(http.StatusOK, tplSettingsBlockedUsers)
+}
+
+func BlockedUsersPost(ctx *context.Context) {
+	shared_user.BlockedUsersPost(ctx, ctx.Doer)
+	if ctx.Written() {
+		return
+	}
+
+	ctx.Redirect(setting.AppSubURL + "/user/settings/blocked_users")
+}