unittest using externally managed database (#9400)

* MM-12083: unittest using externally managed database

* cherry-pick Makefile changes from @cpanato

* Jenkins changes (#9915)

* add docker compose

* udpate

* when using minio dont need to set the region

* update

* add wait for it script

* using old minio

* add new jenkins file

* update makefile

* add dockerfile

* rename the docker-compose proj to avoid colision (#9917)

* rename the docker-compose proj to avoid colision

* enable debug

* enable debug to double checkt the branchs and fix docker-compose name (#9919)

* add ee hash to check (#9920)

* fix name (#9921)

* update jenkins file to push from branch and prs

* if a new push comes in stop the running build

* split mysql and postgres variables

* add script to run jenkins-like env in local dev env

* update docker-compose project name to use uuid to make it more randon

* fix DCNAME definition

* update elasticsearch docker image

* revert test

* tidy up stages, and wait for mysql differently

* update docker image and add check for postgres

* checking if is ready

* update docker compose to have a wait for deps

* add readme and rename dockerfile

* fix -unittest setup

* using mm docker image

* restore parallel unit tests at the package level

Spin up a dedicated database for each package under test to avoid races in accessing the same tables.
Simplify the interface for configuring the test database to just a DSN instead of multiple exports for each field.

* try to work around root mysql access in CI

* update local-test-env.sh too

* MYSQL_ROOT_HOST: %

* fix missing quotes

* setting some memory limits for mysql

* revert memory docker compose does not support

* fix env name for postgres

* expose errors in app/export_test.go

* fix test label, better error checking on teardown

* increase query timeout for tests

* fix export_test

* update local dev script

* add configurable mysql root passwd

build/README.md

@@ -0,0 +1,8 @@
+## About this folder
+
+This folder contains some files that we use to build the `mattermost-server` using `Jenkins` and other files like privacy policy and licenses.
+
+PRs opened against the `mattermost-server` repository will use the file called `Jenkinsfile.pr`
+
+The `Dockerfile` in this folder (`Dockerfile.buildenv`) is the build environment for our current builds you can find the docker image to downalod [here](https://hub.docker.com/r/mattermost/mattermost-build-server/tags/) or build your own.
+