Support also `pnpm audit --json`

[TaylorHo]

Support pnpm audit Output

This package currently only works with npm audit --json, but pnpm is widely used and has a different output format. It also changes the file location in SARIF exports for vulnerable URIs.

We need to add support for pnpm audit to ensure compatibility and allow pnpm users to use this package smoothly.

[TaylorHo]

Already working on branch feature/v5-pnpm-and-yarn-support.

After finalizing #24, the PR will be merged and issues closed.