Expose option to suppress output from hooks runner

From https://github.com/GoogleContainerTools/skaffold/pull/6337#discussion_r681211816:

we definitely can't use the deploy mute setting since the application logs are manually muted in-between dev loops using this setting. This will have the effect of never actually printing the container hook log messages, since the container hooks are always executed in-between dev loops.

As is, output from executing hooks scripts will always be surfaced to users, even when the logs for individual phases are suppressed. We should either:

• tie the output of the hooks to the associated phase (e.g. pre-/post-deploy hooks tied to the deploy phase; or,
• add an option to explicitly suppress output from hooks themselves, independent of their associated phase

Option 1 seems a bit cleaner, but Option 2 seems useful for users who have hooks with particularly verbose output.