Plugins: Fix catalog permissions for org and server admins (#37504)

* simplify toggle + add link to server admin

* feat(catalog): org admins can configure plugin apps, cannot install/uninstall plugins

* fix(catalog): dont show buttons if user doesn't have install permissions

* feat(catalog): cater for accessing catalog via /plugins and /admin/plugins

* feat(catalog): use location for list links and match.url to define breadcrumb links

* test(catalog): mock isGrafanaAdmin for PluginDetails tests

* test(catalog): preserve default bootdata in PluginDetails mock

* refactor(catalog): move orgAdmin check out of state and make easier to reason with

Co-authored-by: Will Browne <will.browne@grafana.com>

pkg/api/index.go

@@ -388,6 +388,12 @@ func (hs *HTTPServer) buildAdminNavLinks(c *models.ReqContext) []*dtos.NavLink {
 		})
 	}
 
+	if hs.Cfg.PluginAdminEnabled && hasAccess(ac.ReqGrafanaAdmin, ac.ActionPluginsManage) {
+		adminNavLinks = append(adminNavLinks, &dtos.NavLink{
+			Text: "Plugins", Id: "admin-plugins", Url: hs.Cfg.AppSubURL + "/admin/plugins", Icon: "plug",
+		})
+	}
+
 	return adminNavLinks
 }