slither-read-storage should accept solc Standard JSON

### Describe the desired feature

Please add support for feeding Solidity Standard JSON directly into slither-read-storage, so users can extract storage layout/slots from JSON exports without reconstructing a source tree or flattening to .sol.
This aligns with Slither’s documented storage tooling and crytic-compile’s existing Standard-JSON platform.

Current behavior

Running inside the Trail of Bits toolbox container:
docker run --rm -it -v "C:\0424:/share" ghcr.io/trailofbits/eth-security-toolbox:nightly \
bash -lc 'cd /share && solc-select install 0.4.25 && solc-select use 0.4.25 && \
slither-read-storage 0424.json --contract-name TestVariables --json /share/output_slither.json'

Actual result:
slither.exceptions.SlitherError: Invalid compilation:
0424.json is not the expected format '.sol'
So slither-read-storage rejects .json inputs, even when they are valid solc --standard-json

Expected behavior
Allow slither-read-storage to consume Standard JSON directly