Simplyfing config for Dynamic Grid

[diemol]

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Description

Until now, the user had to describe through the config.toml file the paths to be used inside the container and on the host. This could be error-prone. Now, we inspect the container and identify the host path mounted to /opt/selenium/assets, and then use that path to mount it on the video container.

Motivation and Context

Simplifies the configuration for Dynamic Grid, making it less error prone.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the contributing document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.