[TIMOB-25340] Hyperloop: Move to using auto-required 'hooks' folder, not plugin

We currently use a 'plugins' folder inside our hyperloop release to handle CLI hooks to do the inspection of source for hyperloop usage, generation of metaphase, etc. This requires jumping through some hoops to get the build to include the plugins folder and it's hooks; and it requires the user add the hyperloop plugin to their tiapp.xml. Given that we now support implicit hooks in a module from TIMOB-24041, we should move straight to simple hooks and deprecate the plugin. To avoid a breaking change we can add a plugin whose hook simply spits out the deprecation notice that the plugin should no longer be added to the tiapp.xml. This will simplify the builds, so we shouldn't need to unzip and re-zip to hack the plugins folder inside (in our Jenkinsfile), and should remove one more step from using hyperloop in apps.