fix: Unable to create project from local path of template v2

[rosen-vladimirov]

pacote package does not work very well with relative paths, so ensure we pass full path to the extractPackage method. When trying to pass .tgz with relative path for template and the .tgz is located next to .git dir, the pacote package tries to download the repository instead of using the local .tgz package. Once full path is passed, it works correctly.

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?

Follow the steps below and you'll receive an error:

1. Clone any v2 template repo, for example https://github.com/rosen-vladimirov/test-tns-template-v2: git clone https://github.com/rosen-vladimirov/test-tns-template-v2
2. Pack the template: cd test-tns-template-v2 && npm pack && cd .. - this will produce a test-tns-template-v2.tgz in test-tns-template-v2 dir.
3. From any outside dir (not the test-tns-template-v2) try to create a new project by passing relative path to the .tgz: tns create myApp --template test-tns-template-v2/test-tns-template-v2.tgz
   The last operation will fail with error:

Error while executing:
/usr/local/bin/git ls-remote -h -t ssh://[email protected]/test-tns-template-v2/test-tns-template-v2-1.0.0.tgz.git

ERROR: Repository not found.
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

exited with error code: 128

What is the new behavior?

You can successfully create a project with the steps above