[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/user_agent_test.go

@@ -47,6 +47,7 @@ var testUserAgents = []testUserAgent{
 }
 
 func TestGetPlatformName(t *testing.T) {
+	mainHelper.Parallel(t)
 	expected := []string{
 		"Windows",
 		"Macintosh",
@@ -88,6 +89,7 @@ func TestGetPlatformName(t *testing.T) {
 }
 
 func TestGetOSName(t *testing.T) {
+	mainHelper.Parallel(t)
 	expected := []string{
 		"Windows 7",
 		"Mac OS",
@@ -129,6 +131,7 @@ func TestGetOSName(t *testing.T) {
 }
 
 func TestGetBrowserName(t *testing.T) {
+	mainHelper.Parallel(t)
 	expected := []string{
 		"Firefox",
 		"Chrome",
@@ -170,6 +173,7 @@ func TestGetBrowserName(t *testing.T) {
 }
 
 func TestGetBrowserVersion(t *testing.T) {
+	mainHelper.Parallel(t)
 	expected := []string{
 		"40.1",
 		"60.0.3112", // Doesn't report the fourth part of the version