[SCM-1013] Add skip parameter to all goals

**[Richard Eckart de Castilho](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=rec)** opened **[SCM-1013](https://issues.apache.org/jira/browse/SCM-1013?redirect=false)** and commented

Currently, the only way to conditionally execute this plugin is by either putting it into a profile or by putting it into a conditionally included submodule. But profile-based activation may not be flexible enough and putting it into a conditionally included submodule is quite inconvenient.

Most Maven goals have a "skip" parameter that can be used to control them. It would be good if the Maven SVM goals would follow that approach as well.

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No further details from [SCM-1013](https://issues.apache.org/jira/browse/SCM-1013?redirect=false)

The issue names no files or tests. Start by locating all Maven SVM goal implementations and their existing tests, then trace how goal parameters are defined and applied. Done means every goal supports a skip parameter that conditionally prevents execution, with tests covering the skipped and normal paths.

Written by the indexing model from the issue text.