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](https://github.com/go-gitea/gitea/assets/1666336/4ed884f3-e06a-4862-afd3-3b8aa2488dc6)


![grafik](https://github.com/go-gitea/gitea/assets/1666336/ae6d4981-f252-4f50-a429-04f0f9f1cdf1)


![grafik](https://github.com/go-gitea/gitea/assets/1666336/ca153599-5b0f-4b4a-90fe-18bdfd6f0b6b)

---------

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

templates/org/settings/blocked_users.tmpl

@@ -0,0 +1,5 @@
+{{template "org/settings/layout_head" (dict "ctxData" . "pageClass" "organization settings blocked_users")}}
+<div class="org-setting-content">
+	{{template "shared/user/blocked_users" .}}
+</div>
+{{template "org/settings/layout_footer" .}}

templates/org/settings/navbar.tmpl

@@ -17,6 +17,9 @@
 			{{ctx.Locale.Tr "settings.applications"}}
 		</a>
 		{{end}}
+		<a class="{{if .PageIsSettingsBlockedUsers}}active {{end}}item" href="{{.OrgLink}}/settings/blocked_users">
+			{{ctx.Locale.Tr "user.block.list"}}
+		</a>
 		{{if .EnablePackages}}
 		<a class="{{if .PageIsSettingsPackages}}active {{end}}item" href="{{.OrgLink}}/settings/packages">
 			{{ctx.Locale.Tr "packages.title"}}