MM-53355: tidy up plugins (#24194)

* remove feature flag managed plugins

* remove unneeded plugin blocklist

* remove unnecessary wrappers

* documentation and logging improvements

* avoid use of global logger
* leverage wrapped loggers (e.g. consistently log `plugin_id`)
* promote some logs from `Debug` to `Info` for better visibility.
* extract installPluginToFilestore
* rename some variables for consistency / clarity

* make generated

server/public/plugin/environment.go

@@ -103,34 +103,9 @@ func scanSearchPath(path string) ([]*model.BundleInfo, error) {
 	return ret, nil
 }
 
-var pluginIDBlocklist = map[string]bool{
-	"com.mattermost.plugin-incident-response":   true,
-	"com.mattermost.plugin-incident-management": true,
-}
-
-func PluginIDIsBlocked(id string) bool {
-	_, ok := pluginIDBlocklist[id]
-	return ok
-}
-
 // Returns a list of all plugins within the environment.
 func (env *Environment) Available() ([]*model.BundleInfo, error) {
-	rawList, err := scanSearchPath(env.pluginDir)
-	if err != nil {
-		return nil, err
-	}
-
-	// Filter any plugins that match the blocklist
-	filteredList := make([]*model.BundleInfo, 0, len(rawList))
-	for _, bundleInfo := range rawList {
-		if PluginIDIsBlocked(bundleInfo.Manifest.Id) {
-			env.logger.Debug("Plugin ignored by blocklist", mlog.String("plugin_id", bundleInfo.Manifest.Id))
-		} else {
-			filteredList = append(filteredList, bundleInfo)
-		}
-	}
-
-	return filteredList, nil
+	return scanSearchPath(env.pluginDir)
 }
 
 // Returns a list of prepackaged plugins available in the local prepackaged_plugins folder.