feat: add ss2 scene to launch setup

[mozhoku]

Description

Addition of ss2 scene to the current Loader scene for ease of usage and distribution.
ss2 is used by OpenSCENEARIO.

• Simulator scenes tracked with a scriptable object. It loads the active scenes in the Build Settings when opening the project. Saves these to an asset in the Resources folder with a scriptable object named SceneMetadataUpdater. And uses it in the runtime for checking whether a scene is used for scenario simulator or not.

Can be extended for future use.

Example:

Related links

• Add scenario simulator scene to the multi scene setup  #141

Tests performed

Not applicable.

Effects on system behavior

Not applicable.

Notes for reviewers

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[github-actions]

Documentation URL: https://autowarefoundation.github.io/AWSIM-Labs/pr-142/
Modified URLs:

• https://autowarefoundation.github.io/AWSIM-Labs/pr-142/Components/ScenarioSimulation/PreparingTheConnectionBetweenAWSIMAndScenarioSimulator/
• https://autowarefoundation.github.io/AWSIM-Labs/pr-142/Components/ScenarioSimulation/SetupUnityProjectForScenarioSimulation/
• https://autowarefoundation.github.io/AWSIM-Labs/pr-142/GettingStarted/UsingOpenSCENARIO/