Link to portal comparison page in markdown comment

[matejchalk]

User story

As a user who uploads reports to the Code PushUp portal, I would like there to be a link from the PR comment to the full comparison in the portal.

Related issues

• epic: https://github.com/code-pushup/portal/issues/376
• prerequisite: https://github.com/code-pushup/portal/issues/377

Acceptance criteria

• if upload config is present, compare command should include portal link in markdown summary