Create a MariaDB CS Release dashboard

Flask web page integrated in master-web via Buildbot WSGI module.

Track bb-<series>-release branches and report the status of the latest changes on these branches.

The bb-<series>-release branches are reused every release. Track the builds on these branches if the planned MariaDB Server version in Jira (planned) == mariadb_version property of the most recent tarball-docker build on the branches in scope.

Data sources:

• Jira (releases) for planned upcoming CS releases.
• Buildbot REST API - build details

Layout:

• top: overall per branch status, mark a release as either: Releseable (all builds green), Needs Attention (normal builds failure), Unreleaseable (autobake builder failure), Pending (no builds for the version yet or not all builds completed)
• bottom: detailed build status per branch, commit. Table format with each build and their status.

Builds in scope:

• all builds tagged with "release_packages"

Branches in scope:

• bb-<series>-release branches