Unit functions added to dashboard

[nikhilsinhaparseable]

dashboard.json updated to have tick_config that contains list of column names and their unit names

sample json -
{ "version": "v1", "name": "helloa", "description": "ahdkadkadvnasdsa", "dashboard_id": "admin.1724033591071", "user_id": "admin", "time_filter": null, "refresh_interval": 60, "tiles": [ { "name": "final", "tile_id": "admin.1724033591071255", "description": "sdsds", "query": "select * from teststream LIMIT 100", "order": 2, "visualization": { "visualization_type": "donut-chart", "circular_chart_config": { "name_key": "app_meta", "value_key": "device_id" }, "graph_config": null, "size": "sm", "color_config": [], "tick_config": [{"key": "device_id", "unit": "unit_name"}] } } ] }

Fixes #XXXX.

Description

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This PR has:

• been tested to ensure log ingestion and log query works.
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added documentation for new or modified features or behaviors.