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/channels/api4/post.go

@@ -773,18 +773,9 @@ func searchPosts(c *Context, w http.ResponseWriter, r *http.Request, teamId stri
 		includeDeletedChannels = *params.IncludeDeletedChannels
 	}
 
-	modifier := ""
-	if params.Modifier != nil {
-		modifier = *params.Modifier
-	}
-	if modifier != "" && modifier != model.ModifierFiles && modifier != model.ModifierMessages {
-		c.SetInvalidParam("modifier")
-		return
-	}
-
 	startTime := time.Now()
 
-	results, err := c.App.SearchPostsForUser(c.AppContext, terms, c.AppContext.Session().UserId, teamId, isOrSearch, includeDeletedChannels, timeZoneOffset, page, perPage, modifier)
+	results, err := c.App.SearchPostsForUser(c.AppContext, terms, c.AppContext.Session().UserId, teamId, isOrSearch, includeDeletedChannels, timeZoneOffset, page, perPage)
 
 	elapsedTime := float64(time.Since(startTime)) / float64(time.Second)
 	metrics := c.App.Metrics()