[MM-62408] Server Code Coverage with Fully Parallel Tests (#30078)

* TestPool

* Store infra

* Store tests updates

* Bump maximum concurrent postgres connections

* More infra

* channels/jobs

* channels/app

* channels/api4

* Protect i18n from concurrent access

* Replace some use of os.Setenv

* Remove debug

* Lint fixes

* Fix more linting

* Fix test

* Remove use of Setenv in drafts tests

* Fix flaky TestWebHubCloseConnOnDBFail

* Fix merge

* [MM-62408] Add CI job to generate test coverage (#30284)

* Add CI job to generate test coverage

* Remove use of Setenv in drafts tests

* Fix flaky TestWebHubCloseConnOnDBFail

* Fix more Setenv usage

* Fix more potential flakyness

* Remove parallelism from flaky test

* Remove conflicting env var

* Fix

* Disable parallelism

* Test atomic covermode

* Disable parallelism

* Enable parallelism

* Add upload coverage step

* Fix codecov.yml

* Add codecov.yml

* Remove redundant workspace field

* Add Parallel() util methods and refactor

* Fix formatting

* More formatting fixes

* Fix reporting

server/channels/app/web_broadcast_hooks_test.go

@@ -13,6 +13,7 @@ import (
 )
 
 func TestAddMentionsHook_Process(t *testing.T) {
+	mainHelper.Parallel(t)
 	hook := &addMentionsBroadcastHook{}
 
 	userID := model.NewId()
@@ -51,6 +52,7 @@ func TestAddMentionsHook_Process(t *testing.T) {
 }
 
 func TestAddFollowersHook_Process(t *testing.T) {
+	mainHelper.Parallel(t)
 	hook := &addFollowersBroadcastHook{}
 
 	userID := model.NewId()
@@ -88,6 +90,7 @@ func TestAddFollowersHook_Process(t *testing.T) {
 }
 
 func TestPostedAckHook_Process(t *testing.T) {
+	mainHelper.Parallel(t)
 	hook := &postedAckBroadcastHook{}
 	userID := model.NewId()
 	webConn := &platform.WebConn{
@@ -190,6 +193,7 @@ func TestPostedAckHook_Process(t *testing.T) {
 }
 
 func TestAddMentionsAndAddFollowersHooks(t *testing.T) {
+	mainHelper.Parallel(t)
 	addMentionsHook := &addMentionsBroadcastHook{}
 	addFollowersHook := &addFollowersBroadcastHook{}
 
@@ -223,6 +227,7 @@ func TestAddMentionsAndAddFollowersHooks(t *testing.T) {
 }
 
 func TestPermalinkBroadcastHook(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t).InitBasic()
 	defer th.TearDown()