Per VPC site2site.vpn.vpngateway.connection.limit

##### ISSUE TYPE

* Improvement Request
* Enhancement Request

##### COMPONENT NAME

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VR,API,UI
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##### SUMMARY

The configuration site2site.vpn.vpngateway.connection.limit is only available at the global level currently, an operator may want to set specific limits at VPC level or VPC offering level. Provide an option to override the site2site.vpn.vpngateway.connection.limit at VPC and VPC offering levels.

Start by tracing how the global site2site.vpn.vpngateway.connection.limit setting is represented and applied across the VR, API, and UI components. Determine the configuration paths for VPC and VPC offering levels, then define how an override should interact with the global value. Done means both levels can override the global limit and the behavior is covered across the affected components.

Written by the indexing model from the issue text.