MM-24133: Migrate AppError from bot_store.go (#14339)

* MM-24135: Migrate AppError from SaveChannel/channel_store.go

This is the first POC of migration of store app errors to plain error.

We create a few basic error types in the store package and use
them to return the errors from store methods. In the app layer,
we inspect the error and re-create the exact app errors. This lets
us preserve the same error content, but yet move to plain errors.

Since this is a gradual migration, this means that the error inspection
code will be duplicated across the app layer whenever a store method
is invoked. But all of that should go away once we start propagating
the errors higher up the hierarchy.

There have been a significant amount of changes in the storetest and searchtest
layer, primarily because we have to rename the err variable now that it is of
a different type.

* Addressed review comments

* MM-24132: Migrate AppError from SaveDirectChannel/channel_store.go

This PR migrates 2 new methods SaveDirectChannel and CreateDirectChannel
to return error instead of AppError.

We also need to handle the error internally in SaveMultipleMember for now
until that is migrated too.

* MM-24133: Migrate AppError from bot_store.go

* Fix errors

* Fix err

* Fix bad return

* Fix vet errors

* Fix incorrect error check

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

store/timer_layer.go

@@ -377,7 +377,7 @@ func (s *TimerLayerAuditStore) Save(audit *model.Audit) *model.AppError {
 	return resultVar0
 }
 
-func (s *TimerLayerBotStore) Get(userId string, includeDeleted bool) (*model.Bot, *model.AppError) {
+func (s *TimerLayerBotStore) Get(userId string, includeDeleted bool) (*model.Bot, error) {
 	start := timemodule.Now()
 
 	resultVar0, resultVar1 := s.BotStore.Get(userId, includeDeleted)
@@ -393,7 +393,7 @@ func (s *TimerLayerBotStore) Get(userId string, includeDeleted bool) (*model.Bot
 	return resultVar0, resultVar1
 }
 
-func (s *TimerLayerBotStore) GetAll(options *model.BotGetOptions) ([]*model.Bot, *model.AppError) {
+func (s *TimerLayerBotStore) GetAll(options *model.BotGetOptions) ([]*model.Bot, error) {
 	start := timemodule.Now()
 
 	resultVar0, resultVar1 := s.BotStore.GetAll(options)
@@ -409,7 +409,7 @@ func (s *TimerLayerBotStore) GetAll(options *model.BotGetOptions) ([]*model.Bot,
 	return resultVar0, resultVar1
 }
 
-func (s *TimerLayerBotStore) PermanentDelete(userId string) *model.AppError {
+func (s *TimerLayerBotStore) PermanentDelete(userId string) error {
 	start := timemodule.Now()
 
 	resultVar0 := s.BotStore.PermanentDelete(userId)
@@ -425,7 +425,7 @@ func (s *TimerLayerBotStore) PermanentDelete(userId string) *model.AppError {
 	return resultVar0
 }
 
-func (s *TimerLayerBotStore) Save(bot *model.Bot) (*model.Bot, *model.AppError) {
+func (s *TimerLayerBotStore) Save(bot *model.Bot) (*model.Bot, error) {
 	start := timemodule.Now()
 
 	resultVar0, resultVar1 := s.BotStore.Save(bot)
@@ -441,7 +441,7 @@ func (s *TimerLayerBotStore) Save(bot *model.Bot) (*model.Bot, *model.AppError)
 	return resultVar0, resultVar1
 }
 
-func (s *TimerLayerBotStore) Update(bot *model.Bot) (*model.Bot, *model.AppError) {
+func (s *TimerLayerBotStore) Update(bot *model.Bot) (*model.Bot, error) {
 	start := timemodule.Now()
 
 	resultVar0, resultVar1 := s.BotStore.Update(bot)