Remove command palette POC (#24044)

* Revert "POC: Cross-team recent search (#20027)"

This reverts commit aa59c28b04, preserving
a few code tidyings unrelated to the original PR.

* Revert "Add feature flag for command palette (#20011)"

This reverts commit c78c5ce3f3.

server/public/model/search_params.go

@@ -33,7 +33,7 @@ type SearchParams struct {
 	IncludeDeletedChannels bool     `json:"include_deleted_channels,omitempty"`
 	TimeZoneOffset         int      `json:"timezone_offset,omitempty"`
 	// True if this search doesn't originate from a "current user".
-	SearchWithoutUserId bool   `json:"search_without_userid,omitempty"`
+	SearchWithoutUserId bool   `json:"search_without_user_id,omitempty"`
 	Modifier            string `json:"modifier"`
 }