feat: added agent rust client generation

public/agent-client/.openapi-generator/FILES

@@ -0,0 +1,21 @@
+.gitignore
+.travis.yml
+Cargo.toml
+README.md
+docs/NginxAgentApi.md
+docs/StatusResp.md
+docs/ValidateAndReloadBody.md
+docs/ValidateAndReloadResp.md
+docs/ValidateBody.md
+docs/WriteConfigBody.md
+git_push.sh
+src/apis/configuration.rs
+src/apis/mod.rs
+src/apis/nginx_agent_api.rs
+src/lib.rs
+src/models/mod.rs
+src/models/status_resp.rs
+src/models/validate_and_reload_body.rs
+src/models/validate_and_reload_resp.rs
+src/models/validate_body.rs
+src/models/write_config_body.rs