Move the plugin configuration to its own page

### Dependencies

### Feature Request
The plugin is configurable under **Manage Jenkins** page. However, since the plugin as a whole (as a source and as a sink) requires a good amount of configuration, it reduces readability since there already is a lot of other things to configure inside the **Manage Jenkins page**

This feature suggests moving the configuration from **Global Configuration/Manage Jenkins** to its own page. Some plugins in the Jenkins ecosystem use their own page inside Jenkins which makes the UI cleaner, and makes it easy for users to enter the info needed for the plugin's configuration.
Some examples of such plugin are:
* https://github.com/jenkinsci/configuration-as-code-plugin
* https://github.com/jenkinsci/folder-auth-plugin
* https://github.com/jenkinsci/cloud-stats-plugin
* https://github.com/jenkinsci/monitoring-plugin

These plugins extend from the **Management Link** class which allows these plugins to have their own configurable page. If the CloudEvents plugin had its own configurable page, it will make configuring the plugin easier.