Add Multi ASICs support for GCU HLD.

[xincunli-sonic]

This PR introduces Multi-ASIC support for SONiC's Generic Configuration Update and Rollback feature. It enhances the existing design to handle configurations across multiple ASICs and the host namespace.

1. The changes make configuration management tools namespace-aware, allowing them to apply configuration patches specifically to global, ASIC, or host scopes.
2. The JSON Patch format is extended to include namespace identifiers, enabling targeted configuration updates.
3. This PR also updates CLI options for namespace specification and improves validation, verification, and testing for Multi-ASIC scenarios, ensuring reliable configuration management in complex SONiC deployments.

Code change PRs

1. apply-patch: https://github.com/sonic-net/sonic-utilities/pull/3219

[xincunli-sonic]

@qiluo-msft, can you help merge, Thanks! #Resolved

[qiluo-msft]

| 1 | Add a new table. |

I think most testcases could be applicable to multi-asic. And there should be some special testcases for multi-asic, like "add a new ASIC config subtree", "add a new ASIC with empty config", etc. #Closed

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Refers to: doc/config-generic-update-rollback/SONiC_Generic_Config_Update_and_Rollback_Design.md:1028 in 38f70d2. [](commit_id = 38f70d2d1e1a12b9f41c96313d70da81e2596eee, deletion_comment = False)

[qiluo-msft]

Please resolve conflict.

[xincunli-sonic]

Used forked repo to recreate a new PR: https://github.com/sonic-net/SONiC/pull/1671