Add prototype of pipeline api using connect

This includes refactoring of the http listener to use
a custom mux.

proto/get_runner/v1/get_runner.proto

@@ -0,0 +1,17 @@
+syntax = "proto3";
+
+package get_runner.v1;
+
+option go_package = "git.ohea.xyz/cursorius/server/proto/gen/get_runner/v1;get_runnerv1";
+
+message GetRunnerRequest {
+  string tag = 1;
+}
+
+message GetRunnerResponse {
+  bool success = 1;
+}
+
+service GetRunnerService {
+  rpc GetRunner(GetRunnerRequest) returns (GetRunnerResponse) {}
+}