MM-64330 - filter abac users in channel invite (#31219)

* MM-64330 - filter abac users in channel invite

* implement cursor functionality for abac user filtering

* remove unnecessary comments

* refactor the backend implementation simplifying the functions

* refactor api to use opts as parameters, rename function

* add missing translation

* remove unnecesary test code

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/api4/user.go

@@ -840,7 +840,13 @@ func getUsers(c *Context, w http.ResponseWriter, r *http.Request) {
 			return
 		}
 
-		profiles, appErr = c.App.GetUsersNotInChannelPage(inTeamId, notInChannelId, groupConstrainedBool, c.Params.Page, c.Params.PerPage, c.IsSystemAdmin(), restrictions)
+		if ok, _ := c.App.ChannelAccessControlled(c.AppContext, notInChannelId); ok {
+			// Get cursor_id from query parameters for cursor-based pagination
+			cursorId := r.URL.Query().Get("cursor_id")
+			profiles, appErr = c.App.GetUsersNotInAbacChannel(c.AppContext, inTeamId, notInChannelId, groupConstrainedBool, cursorId, c.Params.PerPage, c.IsSystemAdmin(), restrictions)
+		} else {
+			profiles, appErr = c.App.GetUsersNotInChannelPage(inTeamId, notInChannelId, groupConstrainedBool, c.Params.Page, c.Params.PerPage, c.IsSystemAdmin(), restrictions)
+		}
 	} else if notInTeamId != "" {
 		if !c.App.SessionHasPermissionToTeam(*c.AppContext.Session(), notInTeamId, model.PermissionViewTeam) {
 			c.SetPermissionError(model.PermissionViewTeam)