Hide unused ports from ports view(s)

Introduce alternative port state / hide unused ports from list.

Currently, the port states we have are:

1. open - private
2. open - public
3. not served

This last category not served contains three types of ports (that I can think of):

1. Those defined in YAML - but not currently served - These could be marked differently, e.g. configured - not served
2. Those not defined in YAML, but are required - e.g. user has opened them previously, marked as public, and is starting/stopping a process, e.g. not configured - not served.
3. Not defined in YAML - not required - There is currently no way to clean up these ports.

By grouping these all together, it's hard to distinguish between each, it also means that we're not encouraging users to update the gitpod.yml where necessary (and push users to config their environment as much as possible).

Potential options/solutions:

1. Break down the not served state to be more explicit
2. Hide all not served ports by default, and only show when served, however allow the user to show them if passing a specific flag to CLI (e.g. gp ports --all) and using a filter in the UI, similar to how dotfiles hide/show when using ls vs ls -a

This issue relates to: https://github.com/gitpod-io/gitpod/issues/10275

Example of enabling a number of ports, and them continuing to show in the ports list.

Start by reading this issue alongside the related issue #10275, then inspect the existing ports views and the gp ports CLI behavior. The issue presents multiple possible directions, so done should be defined by choosing and documenting one behavior for unused ports across the UI and CLI, including how users can reveal them.