[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/opengraph_test.go

@@ -43,6 +43,7 @@ func BenchmarkForceHTMLEncodingToUTF8(b *testing.B) {
 }
 
 func TestMakeOpenGraphURLsAbsolute(t *testing.T) {
+	mainHelper.Parallel(t)
 	for name, tc := range map[string]struct {
 		HTML       string
 		RequestURL string
@@ -128,6 +129,7 @@ func TestMakeOpenGraphURLsAbsolute(t *testing.T) {
 }
 
 func TestOpenGraphDecodeHTMLEntities(t *testing.T) {
+	mainHelper.Parallel(t)
 	og := opengraph.NewOpenGraph()
 	og.Title = "Test's are the best.©"
 	og.Description = "Test's are the worst.©"