fix: use a task execution facade for Gradle task execution

[honourosis]

The current implementation of task execution in AbstractGradleToolDelegate strictly relies on the internals of the External System API. This is not necessary, as there is a correspondingly simple way to execute tasks.

In addition, some of the used methods will be annotated as @Internal and will not be available for use by third-party plugins.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[angelozerr]

Thanks @honourosis

I don't know this code base, so let's me some time to test your PR but it looks good.