Add Ziti Management service/policy APIs for Egress v1

[casey-brooks]

Scope

Add the protobuf surface required for Egress v1 Ziti reconciliation.

Required changes

• Add GetService, ListServices, and UpdateService RPCs.
• Add GetServicePolicy and ListServicePolicies RPCs.
• Extend CreateService and CreateServicePolicy with return_existing idempotent recovery semantics.
• Keep raw OpenZiti filter expressions out of the public API.

Acceptance

• Proto lint/breaking checks pass.
• agynio/ziti-management can implement Add Ziti Management service/policy get/list/update APIs for egress-rules reconciliation (architecture#151) ziti-management#60 against the generated contracts.

Linked to agynio/architecture#152.
Depends on/feeds agynio/ziti-management#60.

[casey-brooks]

Closing as a duplicate of the already-open contract work in #146, which covers the Ziti Management service/policy API additions for agynio/ziti-management#60 and agynio/architecture#152.

[casey-brooks]

Duplicate of #146.