Add responsive size attributes to jsonConfig template

[Copilot]

This PR adds responsive size attributes to the jsonConfig.json template to follow current best practices for ioBroker admin UI layouts.

Changes Made

• Update jsonConfig template to include responsive size attributes
• Update test baselines to reflect the new structure
• Add changelog entry for the change
• Create migration guide with documentation link

The generateSetting function in templates/admin/jsonConfig.json.ts now includes Bootstrap-style responsive size attributes for all input types:

{
  "xs": 12,
  "sm": 12,
  "md": 6,
  "lg": 4,
  "xl": 4
}

These attributes control how form fields are displayed across different screen sizes in the admin UI, providing better responsive design for adapter configuration interfaces.

Before

{
  "type": "text",
  "label": "option1",
  "newLine": true
}

After

{
  "type": "text",
  "label": "option1",
  "newLine": true,
  "xs": 12,
  "sm": 12,
  "md": 6,
  "lg": 4,
  "xl": 4
}

The size attributes are applied consistently to both select and non-select input types. All existing tests continue to pass, and the baseline files have been updated to reflect the new structure.

A migration guide has been created at docs/updates/20250831_jsonconfig_responsive_attributes.md with detailed instructions for updating existing adapters and a link to the official documentation.

Fixes #1121.

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[Apollon77]

@copilot Please add the needed changelog entry and also a migration file for this change. Please link to https://github.com/ioBroker/ioBroker.admin/blob/master/packages/jsonConfig/README.md#layout-options-xllgmdsmxs for details in the migration information

[Copilot]

@copilot Please add the needed changelog entry and also a migration file for this change. Please link to https://github.com/ioBroker/ioBroker.admin/blob/master/packages/jsonConfig/README.md#layout-opt...

Added changelog entry and migration file as requested. The migration guide includes detailed instructions for updating existing adapters and links to the official documentation at https://github.com/ioBroker/ioBroker.admin/blob/master/packages/jsonConfig/README.md#layout-options-xllgmdsmxs. Commit: f7dab0a