fix(gitpod-cli): ports list safe access to exposed url

[andreafalzetti]

Description

This PR fix safe access to port.Exposed.* for both Url and Visibility.

Also, I've refactored the existing logic to determine the status, to be more readable and to follow the vscode implementation

 gp ports list
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x30 pc=0x97c5ae]

goroutine 1 [running]:
github.com/gitpod-io/gitpod/gitpod-cli/cmd.glob..func12(0xfb5fe0, {0xac9654, 0x0, 0x0})
        github.com/gitpod-io/gitpod/gitpod-cli/cmd/ports-list.go:86 +0x3ae
github.com/spf13/cobra.(*Command).execute(0xfb5fe0, {0xff6aa8, 0x0, 0x0})
        github.com/spf13/[email protected]/command.go:856 +0x663
github.com/spf13/cobra.(*Command).ExecuteC(0xfb5ae0)
        github.com/spf13/[email protected]/command.go:960 +0x39d
github.com/spf13/cobra.(*Command).Execute(...)
        github.com/spf13/[email protected]/command.go:897
github.com/gitpod-io/gitpod/gitpod-cli/cmd.Execute()
        github.com/gitpod-io/gitpod/gitpod-cli/cmd/root.go:35 +0x325
main.main()
        github.com/gitpod-io/gitpod/gitpod-cli/main.go:12 +0x17

Related Issue(s)

Fixes #11990

How to test

1. Start a workspace with https://afalz-fix-5d5a7c82e6.preview.gitpod-dev.com/#https://github.com/gitpod-io/empty
2. Run gp ports list and observe nothing is resulted (actually port 3000 is already displayed as non-served by default for some reason)
3. Run curl lama.sh | sh -s — —port 3001
4. Run gp ports list and observe port 3001 being open (private)
5. Run gp ports visibility 3001:public, then run gp ports list and observe port 3001 being open (public)

Release Notes

Bugfix: avoid failure on `ports list` when port is not exposed

Documentation

Werft options:

• /werft with-local-preview
  If enabled this will build install/preview
• /werft with-preview
• /werft with-integration-tests=all
  Valid options are all, workspace, webapp, ide

[felladrin]

ℹ️ I'm reviewing it now!

[felladrin]

Working as described! ✅