feat: use go:embed to embed templates (#1756)

tools/goctl/api/ktgen/apibase.tpl

@@ -0,0 +1,61 @@
+package {{.}}
+
+import com.google.gson.Gson
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.io.BufferedReader
+import java.io.InputStreamReader
+import java.io.OutputStreamWriter
+import java.net.HttpURLConnection
+import java.net.URL
+
+const val SERVER = "http://localhost:8080"
+
+suspend fun apiRequest(
+    method: String,
+    uri: String,
+    body: Any = "",
+    onOk: ((String) -> Unit)? = null,
+    onFail: ((String) -> Unit)? = null,
+    eventually: (() -> Unit)? = null
+) = withContext(Dispatchers.IO) {
+    val url = URL(SERVER + uri)
+    with(url.openConnection() as HttpURLConnection) {
+        connectTimeout = 3000
+        requestMethod = method
+        doInput = true
+        if (method == "POST" || method == "PUT" || method == "PATCH") {
+            setRequestProperty("Content-Type", "application/json")
+            doOutput = true
+            val data = when (body) {
+                is String -> {
+                    body
+                }
+                else -> {
+                    Gson().toJson(body)
+                }
+            }
+            val wr = OutputStreamWriter(outputStream)
+            wr.write(data)
+            wr.flush()
+        }
+
+         try {
+            if (responseCode >= 400) {
+                BufferedReader(InputStreamReader(errorStream)).use {
+                    val response = it.readText()
+                    onFail?.invoke(response)
+                }
+                return@with
+            }
+            //response
+            BufferedReader(InputStreamReader(inputStream)).use {
+                val response = it.readText()
+                onOk?.invoke(response)
+            }
+        } catch (e: Exception) {
+            e.message?.let { onFail?.invoke(it) }
+        }
+    }
+    eventually?.invoke()
+}