Run default addressables build conditionally (#231)

* Add asmdef and Addressable content build in the builder

* Move asmdef content into its own directory

* Mark UnityBuilderAction as Editor-only

dist/default-build-script/Assets/Editor/UnityBuilderAction/Input/ArgumentsParser.cs

@@ -0,0 +1,80 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using UnityEditor;
+
+namespace UnityBuilderAction.Input
+{
+  public class ArgumentsParser
+  {
+    static string EOL = Environment.NewLine;
+    static readonly string[] Secrets = { "androidKeystorePass", "androidKeyaliasName", "androidKeyaliasPass" };
+
+    public static Dictionary<string, string> GetValidatedOptions()
+    {
+      ParseCommandLineArguments(out var validatedOptions);
+
+      if (!validatedOptions.TryGetValue("projectPath", out var projectPath)) {
+        Console.WriteLine("Missing argument -projectPath");
+        EditorApplication.Exit(110);
+      }
+
+      if (!validatedOptions.TryGetValue("buildTarget", out var buildTarget)) {
+        Console.WriteLine("Missing argument -buildTarget");
+        EditorApplication.Exit(120);
+      }
+
+      if (!Enum.IsDefined(typeof(BuildTarget), buildTarget)) {
+        EditorApplication.Exit(121);
+      }
+
+      if (!validatedOptions.TryGetValue("customBuildPath", out var customBuildPath)) {
+        Console.WriteLine("Missing argument -customBuildPath");
+        EditorApplication.Exit(130);
+      }
+
+      const string defaultCustomBuildName = "TestBuild";
+      if (!validatedOptions.TryGetValue("customBuildName", out var customBuildName)) {
+        Console.WriteLine($"Missing argument -customBuildName, defaulting to {defaultCustomBuildName}.");
+        validatedOptions.Add("customBuildName", defaultCustomBuildName);
+      } else if (customBuildName == "") {
+        Console.WriteLine($"Invalid argument -customBuildName, defaulting to {defaultCustomBuildName}.");
+        validatedOptions.Add("customBuildName", defaultCustomBuildName);
+      }
+
+      return validatedOptions;
+    }
+
+    static void ParseCommandLineArguments(out Dictionary<string, string> providedArguments)
+    {
+      providedArguments = new Dictionary<string, string>();
+      string[] args = Environment.GetCommandLineArgs();
+
+      Console.WriteLine(
+        $"{EOL}" +
+        $"###########################{EOL}" +
+        $"#    Parsing settings     #{EOL}" +
+        $"###########################{EOL}" +
+        $"{EOL}"
+      );
+
+      // Extract flags with optional values
+      for (int current = 0, next = 1; current < args.Length; current++, next++) {
+        // Parse flag
+        bool isFlag = args[current].StartsWith("-");
+        if (!isFlag) continue;
+        string flag = args[current].TrimStart('-');
+
+        // Parse optional value
+        bool flagHasValue = next < args.Length && !args[next].StartsWith("-");
+        string value = flagHasValue ? args[next].TrimStart('-') : "";
+        bool secret = Secrets.Contains(flag);
+        string displayValue = secret ? "*HIDDEN*" : "\"" + value + "\"";
+
+        // Assign
+        Console.WriteLine($"Found flag \"{flag}\" with value {displayValue}.");
+        providedArguments.Add(flag, value);
+      }
+    }
+  }
+}