Roll forward: Add `darwinBenchmarkResults` to native-mac-host-tests.

* Also adds XCodeBuildService to make sure we run 1 `xcodebuild` at a time.
* Boots up simulators automatically after discovering the simulator versions.
* Only cleans up the instance of the simulators being used.
* Roll forward for change: Ic7a85974c581b6573f2cbeb34c244bab25e5943b

Test: DIST_DIR=/Users/rahulrav/Workspace/Projects/androidx/out/dist ANDROIDX_PROJECTS=KMP ./gradlew --no-build-cache --no-configuration-cache :collection:collection-benchmark:darwinBenchmarkResults
Change-Id: I2ec1ad91d4b15af7fb79acb56a05258671bdaeb3

• benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/DarwinBenchmarkPlugin.kt[diff]
• benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/DarwinBenchmarkResultsTask.kt[diff]
• benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/GenerateXCodeProjectTask.kt[diff]
• benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/RunDarwinBenchmarksTask.kt[diff]
• benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/XCodeBuildService.kt[Added - diff]
• benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/XCodeSimCtrl.kt[Added - diff]
• benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/xcode/GsonHelpers.kt[Added - diff]
• benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/xcode/XCResultModels.kt[Renamed from benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/xcode/Models.kt - diff]
• benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/xcode/XCodeSimulatorModels.kt[Added - diff]
• benchmark/benchmark-darwin-gradle-plugin/src/main/kotlin/androidx/benchmark/darwin/gradle/xcode/XcResultParser.kt[diff]
• benchmark/benchmark-darwin-gradle-plugin/src/test/kotlin/ModelsTest.kt[diff]
• benchmark/benchmark-darwin-gradle-plugin/src/test/kotlin/XcResultParserTest.kt[diff]
• benchmark/benchmark-darwin-xcode/projects/benchmark-darwin-samples-xcode.yml[diff]
• benchmark/benchmark-darwin-xcode/projects/collection-benchmark-ios.yml[diff]
• busytown/androidx-native-mac-host-tests.sh[diff]