MM-48614: saves priority for drafts (#21752)

* MM-48614: saves priority for drafts

Adds a new column in the drafts table, "priority".
This way we can save post's priority in the draft.

Fixes OmitConnectionId, which when you published a ws event for a user
was getting bypassed.

Fixes Get for drafts returns deleted ones as well, which is needed for
upsert.

* Adds test case for the OmitConnectionId

* Addresses review comments, removes DeleteAt

* Vets

* Adds missing translation

* Re-instates DeleteAt column

* Adds separate case to get draft including deleted

* Fixes Update Draft

* Empty

api4/drafts.go

@@ -120,7 +120,12 @@ func deleteDraft(c *Context, w http.ResponseWriter, r *http.Request) {
 	channelID := c.Params.ChannelId
 
 	draft, err := c.App.GetDraft(userID, channelID, rootID)
-	if err != nil || c.AppContext.Session().UserId != draft.UserId {
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	if c.AppContext.Session().UserId != draft.UserId {
 		c.SetPermissionError(model.PermissionDeletePost)
 		return
 	}

api4/drafts_test.go

@@ -33,7 +33,6 @@ func TestUpsertDraft(t *testing.T) {
 	draft := &model.Draft{
 		CreateAt:  12345,
 		UpdateAt:  12345,
-		DeleteAt:  0,
 		UserId:    user.Id,
 		ChannelId: channel.Id,
 		Message:   "original",
@@ -105,7 +104,6 @@ func TestGetDrafts(t *testing.T) {
 	draft1 := &model.Draft{
 		CreateAt:  00001,
 		UpdateAt:  00001,
-		DeleteAt:  0,
 		UserId:    user.Id,
 		ChannelId: channel1.Id,
 		Message:   "draft1",
@@ -114,7 +112,6 @@ func TestGetDrafts(t *testing.T) {
 	draft2 := &model.Draft{
 		CreateAt:  11111,
 		UpdateAt:  32222,
-		DeleteAt:  0,
 		UserId:    user.Id,
 		ChannelId: channel2.Id,
 		Message:   "draft2",
@@ -180,7 +177,6 @@ func TestDeleteDraft(t *testing.T) {
 	draft1 := &model.Draft{
 		CreateAt:  00001,
 		UpdateAt:  00001,
-		DeleteAt:  0,
 		UserId:    user.Id,
 		ChannelId: channel1.Id,
 		Message:   "draft1",
@@ -190,7 +186,6 @@ func TestDeleteDraft(t *testing.T) {
 	draft2 := &model.Draft{
 		CreateAt:  11111,
 		UpdateAt:  32222,
-		DeleteAt:  0,
 		UserId:    user.Id,
 		ChannelId: channel2.Id,
 		Message:   "draft2",