feat: Updates to check if playbook is installed prior to running any of the commands, updates tests.

Tests/PlaybookClientTests/PlaybookClientTests.swift

@@ -145,6 +145,7 @@ struct PlaybookClientTests: TestCase {
   @Test
   func generateTemplate() async throws {
     try await withCapturingCommandClient("generateTemplate") {
+      $0.fileClient.isDirectory = { _ in true }
       $0.configurationClient = .mock()
       $0.playbookClient = .liveValue
     } run: {
@@ -180,6 +181,7 @@ struct PlaybookClientTests: TestCase {
     operation: @Sendable @escaping () async throws -> Void
   ) async rethrows {
     try await withDependencies {
+      $0.fileClient.isDirectory = { _ in true }
       $0.configurationClient = .mock(configuration)
       $0.commandClient = .capturing(capturing)
       $0.playbookClient = .liveValue