MM-55966 - Update ArrayFromJSON to use LimitedReader (#25510)

* update ArrayFromJSON to use LimitedReader

* update for bad merge

* fix lint errors

* update test code

* update unit tests

* update unit tests

* fix unit tests

* use consts, other cleanup

* add non sorting duplicate check

* set config to default value, then config setting if available

* fix lint errors

* fixes and debugs

* fix log test

* remove setting from Client, add unlimited Parser to client

* a couple more fixes

* another fix

* rename some variables

* remove superflous call

* check for valid MaximumPayloadSize

* update language file

* fix for e2e-tests

* update util function to return error

* lint fix

* update config property name to include unit

* fix for unit test

* add new config to telemetry

* call function to create LimitedReader

* Deprecate old function, use new function name

* return new AppError on failed parse

* return new AppError on failed parse

* return new AppError on failed parse

* add constant for i18n valid constants

* Update server/public/model/utils_test.go

Co-authored-by: Miguel de la Cruz <mgdelacroix@gmail.com>

* Apply suggestions from code review

Co-authored-by: Miguel de la Cruz <mgdelacroix@gmail.com>

* update error variable, remove unnecessary check

* Update function names

* fix errors from merge

* update unit test to create unique ids

---------

Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: Miguel de la Cruz <mgdelacroix@gmail.com>

server/channels/api4/post.go

@@ -504,9 +504,11 @@ func getPost(c *Context, w http.ResponseWriter, r *http.Request) {
 
 // getPostsByIds also sets a header to indicate, if posts were truncated as per the cloud plan's limit.
 func getPostsByIds(c *Context, w http.ResponseWriter, r *http.Request) {
-	postIDs := model.ArrayFromJSON(r.Body)
-
-	if len(postIDs) == 0 {
+	postIDs, err := model.SortedArrayFromJSON(r.Body, *c.App.Config().ServiceSettings.MaximumPayloadSizeBytes)
+	if err != nil {
+		c.Err = model.NewAppError("getPostsByIds", model.PayloadParseError, nil, "", http.StatusBadRequest).Wrap(err)
+		return
+	} else if len(postIDs) == 0 {
 		c.SetInvalidParam("post_ids")
 		return
 	}
@@ -516,9 +518,9 @@ func getPostsByIds(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	postsList, firstInaccessiblePostTime, err := c.App.GetPostsByIds(postIDs)
-	if err != nil {
-		c.Err = err
+	postsList, firstInaccessiblePostTime, appErr := c.App.GetPostsByIds(postIDs)
+	if appErr != nil {
+		c.Err = appErr
 		return
 	}
 
@@ -530,9 +532,9 @@ func getPostsByIds(c *Context, w http.ResponseWriter, r *http.Request) {
 		if val, ok := channelMap[post.ChannelId]; ok {
 			channel = val
 		} else {
-			channel, err = c.App.GetChannel(c.AppContext, post.ChannelId)
-			if err != nil {
-				c.Err = err
+			channel, appErr = c.App.GetChannel(c.AppContext, post.ChannelId)
+			if appErr != nil {
+				c.Err = appErr
 				return
 			}
 			channelMap[channel.Id] = channel