feat: Support OAuth Client Credentials Grant [HEAD-873]

[PeterSchafer]

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What does this PR do?

This PR adds support for the OAuth Client Credentials Grant to the CLI in addition to the already existing Authorization Code Grant. While the latter is still the default OAuth Grant, providing Client ID and Client Secret via cmd Arguments, will switch to the Client Credentials Grant.

Where should the reviewer start?

All of the changes are actually in the go-application-framework, here only minor changes made and tests are added.
snyk/go-application-framework#115

How should this be manually tested?

Authenticate using Client Credentials Grant

snyk auth --auth-type=oauth --client-secret=<SECRET> --client-id=<ID> 

Authenticate using Authorization Code Grant

snyk auth --auth-type=oauth

Any background context you want to provide?

https://datatracker.ietf.org/doc/html/rfc6749#section-4.4

What are the relevant tickets?

HEAD-873

Screenshots

Additional questions

• Risk: low risk, main thing to mention is that all authentication now goes through the auth extension, instead of going to the legacy CLI directly
• Two acceptance tests where removed due to a slightly changed behaviour, they tested for a specific command flag combination and expected to react with a specific not supported message, now they just show the help as it is common if a certain flag is not supported. In this case it was the auth and the help command that where tested with --json-file-output.