feat: provide the DLE container name to control container labels

Description

To determine which DLE a sync instance belongs to:

• find a DLE container name
• create a struct to simplify internal Engine properties management
• provide the DLE container name to control container labels

Related issue

!361 (comment 727172330)

Examples

A snippet of the docker inspection response of a sync instance

"Labels": {
    "dblab_control": "dblab_sync",
    "dblab_instance_id": "c64mvrvku3086hlp2e6g",
    "dblab_engine_name": "dblab_server",
    "maintainer": "postgres.ai"
}

Checklist

• the MR description has been reviewed
• this MR contains text changes and they have been reviewed OR there are no texts changes
• this MR contains GUI/CLI changes and they have been reviewed OR there are no GUI/CLI changes
• this MR contains API changes, specifications reflect those changes and they have been reviewed OR there are no API changes