feat(misconfig): Load misconfiguration specs from bundles

[simar7]

Today we load misconfiguration specs via the trivy-checks dependency as described here.

Since now specs are shipped along with the Trivy checks bundle, we can improve this experience by loading them from the bundle first. In case of any errors, we can fall back to the existing mechanism of loading from the trivy-checks library. This experience will be similar to the one we have with checks today.

The benefit of this approach being that we will be able to decouple the distribution of specs from the release of Trivy, just as how we have done with misconfiguration checks.