[MM-38216] Add API endpoint and adapt search to allow multi-team search (#18371)

* Add API endpoint and adapt search to allow multi-team search

* Refactor handler, refactor sql query to use squirrel, rename app and store functions and add tests

* Fix lint

* Fix search engines and remove unneeded comments

* Fix test

* Remove user from channel after test

app/post.go

@@ -1307,13 +1307,13 @@ func (a *App) SearchPostsInTeam(teamID string, paramsList []*model.SearchParams)
 	})
 }
 
-func (a *App) SearchPostsInTeamForUser(c *request.Context, terms string, userID string, teamID string, isOrSearch bool, includeDeletedChannels bool, timeZoneOffset int, page, perPage int) (*model.PostSearchResults, *model.AppError) {
+func (a *App) SearchPostsForUser(c *request.Context, terms string, userID string, teamID string, isOrSearch bool, includeDeletedChannels bool, timeZoneOffset int, page, perPage int) (*model.PostSearchResults, *model.AppError) {
 	var postSearchResults *model.PostSearchResults
 	paramsList := model.ParseSearchParams(strings.TrimSpace(terms), timeZoneOffset)
 	includeDeleted := includeDeletedChannels && *a.Config().TeamSettings.ExperimentalViewArchivedChannels
 
 	if !*a.Config().ServiceSettings.EnablePostSearch {
-		return nil, model.NewAppError("SearchPostsInTeamForUser", "store.sql_post.search.disabled", nil, fmt.Sprintf("teamId=%v userId=%v", teamID, userID), http.StatusNotImplemented)
+		return nil, model.NewAppError("SearchPostsForUser", "store.sql_post.search.disabled", nil, fmt.Sprintf("teamId=%v userId=%v", teamID, userID), http.StatusNotImplemented)
 	}
 
 	finalParamsList := []*model.SearchParams{}
@@ -1340,14 +1340,14 @@ func (a *App) SearchPostsInTeamForUser(c *request.Context, terms string, userID
 		return model.MakePostSearchResults(model.NewPostList(), nil), nil
 	}
 
-	postSearchResults, nErr := a.Srv().Store.Post().SearchPostsInTeamForUser(finalParamsList, userID, teamID, page, perPage)
+	postSearchResults, nErr := a.Srv().Store.Post().SearchPostsForUser(finalParamsList, userID, teamID, page, perPage)
 	if nErr != nil {
 		var appErr *model.AppError
 		switch {
 		case errors.As(nErr, &appErr):
 			return nil, appErr
 		default:
-			return nil, model.NewAppError("SearchPostsInTeamForUser", "app.post.search.app_error", nil, nErr.Error(), http.StatusInternalServerError)
+			return nil, model.NewAppError("SearchPostsForUser", "app.post.search.app_error", nil, nErr.Error(), http.StatusInternalServerError)
 		}
 	}