Portal upload token (API key) format validation

[vmasek]

User story

As a user,
I want to be sure the token (API key) I set and use for uploading reports to portal is in correct format,
so I will get quick and understandable feedback that my token is missing or missconfigured.

Acceptance criteria

• validate the prefix cp_ should always be present
• validate the hash lenght as it is always 64 hexadecimal characters
• strip possible the unnecessary surrounding quotes
• the logic for validation/stripping should live in the @code-pushup/portal-client package and be consumed by the CLI

Implementation details

A regex of /^cp_[0-9a-f]{64}$/ could be used.
Additional pre-check if token is wrapped in " or ' quotes as this could be done if user copy pastes from code or assumes it needs to be in explicit string format. We could recover easily by stripping the quotes.