feat: filter by channel type when subscribing to all custom events

[juanlu-interdiscount]

This is a follow-up of #53.

When we support to all channels, now we have the ability to apply a filter. Currently the available options are "All events" and "Custom events only". Ideally these options could be fine-tuned, as per the description there are the following "Supported channels: PushTopic, Generic, Platform events, Change Data Capture events and Monitoring events".

The filter options could be:

• All events
• All custom events
• Only PushTopics
• Only Generic Topics
• Only Platform Events
• Only Change Data Capture events
• Only Monitoring events

Use Case: we have a lot of custom platform events that we test and monitor, but we there also are lots of __ChangeEvent in the system that we are not interested in.