fix: unable to start iOS simulator when Android is not setup

[rosen-vladimirov]

In case CLI is used as a library, you need both Android and iOS to be setup in order to start simulator/emulator. The problem is that we check for errors in the setup before actually checking if we have found simulator/emulator with the specified name.
Change the logic and do not raise errors in case the specified name/id is found. This way you can start iOS Simulator without having any Android setup on local machine.

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing: https://github.com/NativeScript/nativescript-cli/blob/master/CONTRIBUTING.md#contribute-to-the-code-base
• Tests for the changes are included.

What is the current behavior?

What is the new behavior?

Fixes/Implements/Closes #[Issue Number].

[rosen-vladimirov]

test cli-templates

[rosen-vladimirov]

test cli-templates