[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/report_test.go

@@ -47,6 +47,7 @@ var testData []model.ReportableObject = []model.ReportableObject{
 }
 
 func TestSaveReportChunk(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t).InitBasic()
 	defer th.TearDown()
 
@@ -69,6 +70,7 @@ func TestSaveReportChunk(t *testing.T) {
 }
 
 func TestCompileReportChunks(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t).InitBasic()
 	defer th.TearDown()
 
@@ -89,8 +91,7 @@ func TestCompileReportChunks(t *testing.T) {
 		require.Nil(t, readErr)
 		require.NotNil(t, bytes)
 
-		expected :=
-			`Name,NumPosts,StartDate
+		expected := `Name,NumPosts,StartDate
 some-name,400,2024-01-01
 some-other-name,500,2023-01-01
 some-other-other-name,600,2022-01-01
@@ -110,6 +111,7 @@ some-other-other-name,600,2022-01-01
 }
 
 func TestCheckForExistingJobs(t *testing.T) {
+	mainHelper.Parallel(t)
 	th := Setup(t).InitBasic()
 	defer th.TearDown()