Fix 'gp open' command to open files in JetBrains Client instead of the backend IDE

[felladrin]

Description

Fix gp open command to open files in JetBrains Client instead of the backend IDE.

These changes also affects gp preview command, so it needs to be tested.

How to test

1. Open the preview environment generated for this branch
2. Choose the Stable version of IntelliJ IDEA as your preferred editor
3. Start a workspace using this repository: https://github.com/gitpod-io/spring-petclinic
4. Verify that the workspace starts successfully
5. Verify that the IDE opens successfully
6. Run gp open .gitignore and confirm it opens the .gitignore file in the editor
7. Run gp open --wait .gitpod.yml and confirm it opens Gitpod Configuration file and will only exit the command line when you click "Release" on the top bar displayed in the editor
8. Run gp preview https://gitpod.io and confirm Gitpod Website opens in your browser
9. Repeat the same steps above, but now using the Latest Release (Unstable) version of IntelliJ IDEA

Release Notes

Fix 'gp open' command to open files in JetBrains Client instead of the backend IDE

Werft options:

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

[akosyakov]

code changes look good to me, but i have not tried

/hold

[felladrin]

I'll publish the screenshots with the results from Preview Environment soon.

[felladrin]

Stable IntelliJ tested ✅

[felladrin]

EAP IntelliJ tested ✅

/unhold

[andreafalzetti]

🚀

Thanks for fixing this ❤️