Pass plugin key from embedders to PluginBase. (#178)
Pass plugin key from embedders to PluginBase. (#178)

Signed-off-by: Takeshi Yoneda <72d3043deb9ea484d21ffcca03f662fa81cbe321@tetrate.io>
proxy-wasm/proxy-wasm-cpp-host,proxy-wasm/proxy-wasm-cpp-host,proxy-wasm/proxy-wasm-cpp-host